ALBERT

Description: Assessing in situ microbial abilities of soils to degrade pesticides is of great interest giving insight in soil filtering capability, which is a key ecosystem function limiting pollution of groundwater. Quantification of pesticide-degrading gene expression by reverse transcription quantitative PCR (RT-qPCR) was tested as a suitable indicator to monitor pesticide biodegradation performances in soil. RNA extraction protocol was optimized to enhance the yield and quality of RNA recovered from soil samples to perform RT-qPCR assays. As a model, the activity of atrazine-degrading communities was monitored using RT-qPCRs to estimate the level of expression of atzD in five agricultural soils showing different atrazine mineralization abilities. Interestingly, the relative abundance of atzD mRNA copy numbers was positively correlated to the maximum rate and to the maximal amount of atrazine mineralized. Our findings indicate that the quantification of pesticide-degrading gene expression may be suitable to assess biodegradation performance in soil and monitor natural attenuation of pesticide.

Description: This unique study describes how Aspergillus japonicus , Penicillium brocae and Purpureocillium lilacinum , three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n -hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5 % w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15–0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

Description: A comprehensive study on the effects of different carbon sources during the bacterial enrichment on the removal performances of benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds when present as a mixture was conducted. Batch BTEX removal kinetic experiments were performed using cultures enriched with individual BTEX compounds or BTEX as a mixture or benzoate alone or benzoate–BTEX mixture. An integrated Monod-type non-linear model was developed and a ratio between maximum growth rate ( μ max ) and half saturation constant (K s ) was used to fit the non-linear model. A higher μ max /K s indicates a higher affinity to degrade BTEX compounds. Complete removal of BTEX mixture was observed by all the enriched cultures; however, the removal rates for individual compounds varied. Degradation rate and the type of removal kinetics were found to be dependent on the type of carbon source during the enrichment. Cultures enriched on toluene and those enriched on BTEX mixture were found to have the greatest μ max /K s and cultures enriched on benzoate had the least μ max /K s . Removal performances of the cultures enriched on all different carbon sources, including the ones enriched on benzoate or benzoate–BTEX mixture were also improved during a second exposure to BTEX. A molecular analysis showed that after each exposure to the BTEX mixture, the cultures enriched on benzoate and those enriched on benzoate–BTEX mixture had increased similarities to the culture enriched on BTEX mixture.

Description: A genetically engineered microorganism (GEM) capable of simultaneously degrading organophosphate and organochlorine pesticides was constructed for the first time by display of organophosphorus hydrolase (OPH) on the cell surface of a hexachlorocyclohexane (HCH)-degrading Sphingobium japonicum UT26. The GEM could potentially be used for removing the two classes of pesticides that may be present in mixtures at contaminated sites. A surface anchor system derived from the truncated ice nucleation protein (INPNC) from Pseudomonas syringae was used to target OPH onto the cell surface of UT26, reducing the potential substrate uptake limitation. The surface localization of INPNC–OPH fusion was verified by cell fractionation, western blot, proteinase accessibility, and immunofluorescence microscopy. Furthermore, the functionality of the surface-exposed OPH was demonstrated by OPH activity assays. Surface display of INPNC–OPH fusion (82 kDa) neither inhibited cell growth nor affected cell viability. The engineered UT26 could degrade parathion as well as γ-HCH rapidly in minimal salt medium. The removal of parathion and γ-HCH by engineered UT26 in sterile and non-sterile soil was also studied. In both soil samples, a mixture of parathion (100 mg kg −1 ) and γ-HCH (10 mg kg −1 ) could be degraded completely within 15 days. Soil treatment results indicated that the engineered UT26 is a promising multifunctional bacterium that could be used for the bioremediation of multiple pesticide-contaminated environments.

Description: Stimulation of native microbial populations in soil by the addition of small amounts of secondary carbon sources (cosubstrates) and its effect on the degradation and theoretical mineralization of DDT [l,l,l-trichloro-2,2-bis( p -chlorophenyl)ethane] and its main metabolites, DDD and DDE, were evaluated. Microbial activity in soil polluted with DDT, DDE and DDD was increased by the presence of phenol, hexane and toluene as cosubstrates. The consumption of DDT was increased from 23 % in a control (without cosubstrate) to 67, 59 and 56 % in the presence of phenol, hexane and toluene, respectively. DDE was completely removed in all cases, and DDD removal was enhanced from 67 % in the control to ~86 % with all substrates tested, except for acetic acid and glucose substrates. In the latter cases, DDD removal was either inhibited or unchanged from the control. The optimal amount of added cosubstrate was observed to be between 0.64 and 2.6 mg C $ {\text{g}}^{ - 1}_{\text{dry soil}} $ . The CO 2 produced was higher than the theoretical amount for complete cosubstrate mineralization indicating possible mineralization of DDT and its metabolites. Bacterial communities were evaluated by denaturing gradient gel electrophoresis, which indicated that native soil and the untreated control presented a low bacterial diversity. The detected bacteria were related to soil microorganisms and microorganisms with known biodegradative potential. In the presence of toluene a bacterium related to Azoarcus , a genus that includes species capable of growing at the expense of aromatic compounds such as toluene and halobenzoates under denitrifying conditions, was detected.

Description: Because benzene, toluene, ethylbenzene, and xylenes (BTEX) and ethanol are important contaminants present in Brazilian gasoline, it is essential to develop technology that can be used in the bioremediation of gasoline-contaminated aquifers. This paper evaluates the performance of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor fed with water containing gasoline constituents under denitrifying conditions. Two HAIB reactors filled with polyurethane foam matrices (5 mm cubes, 23 kg/m 3 density and 95 % porosity) for biomass attachment were assayed. The reactor fed with synthetic substrate containing protein, carbohydrates, sodium bicarbonate and BTEX solution in ethanol, at an Hydraulic retention time (HRT) of 13.5 h, presented hydrocarbon removal efficiencies of 99 % at the following initial concentrations: benzene 6.7 mg/L, toluene 4.9 mg/L, m -xylene and p -xylene 7.2 mg/L, ethylbenzene 3.7 mg/L, and nitrate 60 mg N/L. The HAIB reactor fed with gasoline-contaminated water at an HRT of 20 h showed hydrocarbon removal efficiencies of 96 % at the following initial concentrations: benzene, 4.9 mg/L; toluene, 7.2 mg/L; m -xylene, 3.7 mg/L; and nitrate 400 mg N/L. Microbiological observations along the length of the HAIB reactor fed with gasoline-contaminated water confirmed that in the first segment of the reactor, denitrifying metabolism predominated, whereas from the first sampling port on, the metabolism observed was predominantly methanogenic.

Description: Burkholderia sp. C3, an efficient polycyclic aromatic hydrocarbon degrader, can utilize nine of the ten N -methylcarbamate insecticides including carbaryl as a sole source of carbon. Rapid hydrolysis of carbaryl in C3 is followed by slow catabolism of the resulting 1-naphthol. This study focused on metabolomes and proteomes in C3 cells utilizing carbaryl in comparison to those using glucose or nutrient broth. Sixty of the 867 detected proteins were involved in primary metabolism, adaptive sensing and regulation, transport, stress response, and detoxification. Among the 41 proteins expressed in response to carbaryl were formate dehydrogenase, aldehyde-alcohol dehydrogenase and ethanolamine utilization protein involved in one carbon metabolism. Acetate kinase and phasin were 2 of the 19 proteins that were not detected in carbaryl-supported C3 cells, but detected in glucose-supported C3 cells. Down-production of phasin and polyhydroxyalkanoates in carbaryl-supported C3 cells suggests insufficient carbon sources and lower levels of primary metabolites to maintain an ordinary level of metabolism. Differential metabolomes (~196 identified polar metabolites) showed up-production of metabolites in pentose phosphate pathways and metabolisms of cysteine, cystine and some other amino acids, disaccharides and nicotinate, in contract to down-production of most of the other amino acids and hexoses. The proteomic and metabolomic analyses showed that carbaryl-supported C3 cells experienced strong toxic effects, oxidative stresses, DNA/RNA damages and carbon nutrient deficiency.

Description: Species of the genus Variovorax are often isolated from nitrile or amide-containing organic compound-contaminated soil. However, there have been few biological characterizations of Variovorax and their contaminant-degrading enzymes. Previously, we reported a new soil isolate, Variovorax boronicumulans CGMCC 4969, and its nitrile hydratase that transforms the neonicotinoid insecticide thiacloprid into an amide metabolite. In this study, we showed that CGMCC 4969 is able to degrade acrylamide, a neurotoxicant and carcinogen in animals, during cell growth in a mineral salt medium as well as in its resting state. Resting cells rapidly hydrolyzed 600 mg/L acrylamide to acrylic acid with a half-life of 2.5 min. In in vitro tests, CGMCC 4969 showed plant growth-promoting properties; it produced a siderophore, ammonia, hydrogen cyanide, and the phytohormone salicylic acid. Interestingly, in soil inoculated with this strain, 200 mg/L acrylamide was completely degraded in 4 days. Gene cloning and overexpression in the Escherichia coli strain Rosetta (DE3) pLysS resulted in the production of an aliphatic amidase of 345 amino acids that hydrolyzed acrylamide into acrylic acid. The amidase contained a conserved catalytic triad, Glu59, Lys 134, and Cys166, and an “MRHGDISSS” amino acid sequence at the N-terminal region. Variovorax boronicumulans CGMCC 4969, which is able to use acrylamide for cell growth and rapidly degrade acrylamide in soil, shows promising plant growth-promoting properties. As such, it has the potential to be developed into an effective Bioaugmentation strategy to promote growth of field crops in acrylamide-contaminated soil.

Description: Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe 2+ to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu 2+ was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag + was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag + to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag + resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu 2+ or Ag + suggest inhibition of the key enzyme of FB metabolism—catechol 1,2-dioxygenase.

Description: In the present study, the influence of kaolinite and goethite on microbial degradation of methyl parathion was investigated. We observed that the biodegradation process was improved by kaolinite and depressed by goethite. Calorimetric data further showed that the metabolic activities of degrading cells ( Pseudomonas putida ) were enhanced by the presence of kaolinite and depressed by the presence of goethite. A semipermeable membrane experiment was performed and results supported the above observations: the promotive effect of kaolinite and the inhibition of goethite for microbial degradation was not found when the bacteria was enclosed by semipermeable membrane and had no direct contact with these minerals, suggesting the important function of the contact of cellular surfaces with mineral particles. The relative larger particles of kaolinite were loosely attached to the bacteria. This attachment made the cells easy to use the sorbed substrate and then stimulated biodegradation. For goethite, small particles were tightly bound to bacterial cells and limited the acquisition of substrate and nutrients, thereby inhibiting biodegradation. These results indicated that interfacial interaction between bacterial cells and minerals significantly affected the biodegradation of pesticides.

Description: Although 4- tert -butylphenol (4- t -BP) is a serious aquatic pollutant, its biodegradation in aquatic environments has not been well documented. In this study, 4- t -BP was obviously and repeatedly removed from water from four different environments in the presence of Spirodela polyrrhiza , giant duckweed, but 4- t -BP persisted in the environmental waters in the absence of S. polyrrhiza . Also, 4- t -BP was not removed from autoclaved pond water with sterilized S. polyrrhiza . These results suggest that the 4- t -BP removal from the environmental waters was caused by biodegradation stimulated by the presence of S. polyrrhiza rather than by uptake by the plant. Moreover, Sphingobium fuliginis OMI capable of utilizing 4- t -BP as a sole carbon and energy source was isolated from the S. polyrrhiza rhizosphere. Strain OMI degraded 4- t -BP via a meta -cleavage pathway, and also degraded a broad range of alkylphenols with linear or branched alkyl side chains containing two to nine carbon atoms. Root exudates of S. polyrrhiza stimulated 4- t -BP degradation and cell growth of strain OMI. Thus, the stimulating effects of S. polyrrhiza root exudates on 4- t -BP-degrading bacteria might have contributed to 4- t -BP removal in the environmental waters with S. polyrrhiza . These results demonstrate that the S. polyrrhiza –bacteria association may be applicable to the removal of highly persistent 4- t -BP from wastewaters or polluted aquatic environments.

Description: The biodegradation of heptadecane in five sand columns was modeled using a multiplicative Monod approach. Each column contained 1.0 kg of sand and 2 g of heptadecane, and was supplied with an artificial seawater solution containing nutrients at a flow rate that resulted in unsaturated flow through the column. All nutrients were provided in excess with the exception of nitrate whose influent concentration was 0.1, 0.5, 1.0, 2.5, or 5.0 mg N/L. The experiment was run around 912 h until no measurable oxygen consumption or CO 2 production was observed. The residual mass of heptadecane was measured at the end of the experiments and the biodegradation was monitored based on oxygen consumption and CO 2 production. Biodegradation kinetic parameters were estimated by fitting the model to experimental data of oxygen, CO 2 , and residual mass of heptadecane obtained from the two columns having influent nitrate–N concentration of 0.5 and 2.5 mg/L. Noting that the oxygen and CO 2 measurements leveled off at around 450 h, we fitted the model to these data for that range. The estimated parameters fell in within the range reported in the literature. In particular, the half-saturation constant for nitrate utilization,  $ K_{\text{N}} $ , was estimated to be 0.45 mg N/L, and the yield coefficient was found to be 0.15 mg biomass/mg heptadecane. Using these values, the rest of experimental data from the five columns was predicted, and the model agreed with the observations. There were some consistent discrepancies at large times between the model simulation and observed data in the cases with higher nitrate concentration. One plausible explanation for these differences could be limitation of biodegradation by reduction of the heptadecane–water interfacial area in these columns while the model uses a constant interfacial area.

Description:    White-rot fungi are a group of microorganisms capable of degrading xenobiotic compounds, such as polycyclic aromatic hydrocarbons or synthetic dyes, by means of the action of extracellular oxidative enzymes secreted during secondary metabolism. In this study, the transformation of three anti-inflammatory drugs: diclofenac, ibuprofen and naproxen were carried out by pellets of Phanerochaete chrysosporium in fed-batch bioreactors operating under continuous air supply or periodic pulsation of oxygen. The performance of the fungal reactors was steady over a 30-day treatment and the effect of oxygen pulses on the pellet morphology was evidenced. Complete elimination of diclofenac was achieved in the aerated and the oxygenated reactors, even with a fast oxidation rate in the presence of oxygen (77% after 2 h), reaching a total removal after 23 h. In the case of ibuprofen, this compound was completely oxidized under air and oxygen supply. Finally, naproxen was oxidized in the range of 77 up to 99% under both aeration conditions. These findings demonstrate that the oxidative capability of this microorganism for the anti-inflammatory drugs is not restricted to an oxygen environment, as generally accepted, since the fungal reactor was able to remove these compounds under aerated and oxygenated conditions. This result is very interesting in terms of developing viable reactors for the oxidation of target compounds as the cost of aeration can be significantly reduced. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9494-9 Authors A. I. Rodarte-Morales, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain G. Feijoo, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain M. T. Moreira, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain J. M. Lema, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this work, two novel iron oxidizing bacteria (IOB), namely Gordonia sp. MZ-89 and Enterobacter sp . M01101, were isolated from sewage treatment plants and identified by biochemical and molecular methods. Then, microbially influenced corrosion (MIC) of carbon steel in the presence of these bacteria was investigated. The electrochemical techniques such as potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) were used to measure the corrosion rate and observe the corrosion mechanism. The results showed that the existence of these microorganisms decreased the corrosion potential and enhanced the corrosion rate. Scanning electron microscopy (SEM) images revealed the ground boundary attacks and pitting on carbon steel samples in the presence of these bacteria after polarization. Corrosion scales were identified with X-ray diffraction (XRD). It was demonstrated that these bacteria can greatly affect the crystalline phase of corrosion products that also confirmed by SEM results. It was inferred that these bacteria were responsible for the corrosion of carbon steel, especially in the form of localized corrosion. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9487-8 Authors H. Ashassi-Sorkhabi, Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz, Iran M. Moradi-Haghighi, Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz, Iran G. Zarrini, Microbiology Laboratory, Biology Department, Science Faculty, University of Tabriz, Tabriz, Iran R. Javaherdashti, Department of Civil Engineering, Curtin University of Technology, Perth, WA, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The common grass Calamagrostis epigeions produces a large amount of dead biomass, which remain above the soil surface for many months. In this study, we determined how exposure of dead biomass above the soil affects its subsequent decomposition in soil. Collected dead standing biomass was divided in two parts, the first one (initial litter) was stored in a dark, dry place. The other part was placed in litterbags in the field. The litterbags were located in soil, on the soil surface, or hanging in the air without contact with soil but exposed to the sun and rain. After 1 year of field exposure, litter mass loss and C and N content were measured, and changes in litter chemistry were explored using NMR and thermochemolysis-GC–MS. The potential decomposability of the litter was quantified by burying the litter from the litterbags and the initial litter in soil microcosms and measuring soil respiration. Soil respiration was greater with litter that had been hanging in air than with all other kinds of litter. These finding could not be explained by changes in litter mass or C:N ratio. NMR indicated a decrease in polysaccharides relative to lignin in litter that was buried in soil but not in litter that was placed on soil surface or that was hanging in the air. Thermochemolysis indicated that the syringyl units of the litter lignin were decomposed when the litter was exposed to light. We postulate that photochemical decay of lignin increase decomposability of dead standing biomass. Content Type Journal Article Pages 1-8 DOI 10.1007/s10532-011-9479-8 Authors Jan Frouz, Faculty of Science, Institute for Environmental Studies, Charles University, Benátská 2, 12800 Praha, Czech Republic Tomáš Cajthaml, Faculty of Science, Institute for Environmental Studies, Charles University, Benátská 2, 12800 Praha, Czech Republic Ondřej Mudrák, Institute of soil biology, Biology Center, AS CR, Na Sádkách 7, 37005 České Budějovice, Czech Republic Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Arsenic is a carcinogenic compound widely distributed in the groundwater around the world. The fate of arsenic in groundwater depends on the activity of microorganisms either by oxidizing arsenite (As III ), or by reducing arsenate (As V ). Because of the higher toxicity and mobility of As III compared to As V , microbial-catalyzed oxidation of As III to As V can lower the environmental impact of arsenic. Although aerobic As III -oxidizing bacteria are well known, anoxic oxidation of As III with nitrate as electron acceptor has also been shown to occur. In this study, three As III -oxidizing bacterial strains, Azoarcus sp. strain EC1-pb1, Azoarcus sp. strain EC3-pb1 and Diaphorobacter sp. strain MC-pb1, have been characterized. Each strain was tested for its ability to oxidize As III with four different electron acceptors, nitrate, nitrite, chlorate and oxygen. Complete As III oxidation was achieved with both nitrate and oxygen, demonstrating the novel ability of these bacterial strains to oxidize As III in either anoxic or aerobic conditions. Nitrate was only reduced to nitrite. Different electron donors were used to study their suitability in supporting nitrate reduction. Hydrogen and acetate were readily utilized by all the cultures. The flexibility of these As III -oxidizing bacteria to use oxygen and nitrate to oxidize As III as well as organic and inorganic substrates as alternative electron donors explains their presence in non-arsenic-contaminated environments. The findings suggest that at least some As III -oxidizing bacteria are flexible with respect to electron-acceptors and electron-donors and that they are potentially widespread in low arsenic concentration environments. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9493-x Authors Lucía Rodríguez-Freire, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Wenjie Sun, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Reyes Sierra-Alvarez, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Jim A. Field, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    To reduce the volume of seaweed wastes and extract polysaccharides, seaweed-degrading bacteria were isolated from drifting macroalgae harvested along the coast of Toyama Bay, Japan. Sixty-four bacterial isolates were capable of degrading “Wakame” ( Undaria pinnatifida ) thallus fragments into single cell detritus (SCD) particles. Amongst these, strain 6532A was the most active degrader of thallus fragments, and was capable of degrading thallus fragments to SCD particles within a day. Although the sequence similarity of the 16S rRNA gene of strain 6532A was 100% similar to that of Microbulbifer elongatus JAMB-A7, several distinct differences were observed between strains, including motility, morphology, and utilization of d -arabinose and gelatin. Consequently, strain 6532A was classified as a new Microbulbifer strain, and was designated Microbulbifer sp. 6532A. Strain 6532A was capable of degrading both alginate and cellulose in the culture medium, zymogram analysis of which revealed the presence of multiple alginate lyases and cellulases. To the best of our knowledge, this is the first study to directly demonstrate the existence of these enzymes in Microbulbifer species. Shotgun cloning and sequencing of the alginate lyase gene in 6532A revealed a 1,074-bp open reading frame, which was designated algMsp . The reading frame encoded a PL family seven enzyme composed of 358 amino acids (38,181 Da). With a similarity of 74.2%, the deduced amino acid sequence was most similar to a Saccharophagus enzyme ( alg 7C ). These findings suggest that algMsp in strain 6532A is a novel alginate lyase gene. Content Type Journal Article Pages 1-13 DOI 10.1007/s10532-011-9489-6 Authors Masayuki Wakabayashi, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Akihiro Sakatoku, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Fumio Noda, Sugiyo Co. Ltd, Nanao, Ishikawa 926-8603, Japan Minoru Noda, Sugiyo Co. Ltd, Nanao, Ishikawa 926-8603, Japan Daisuke Tanaka, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Shogo Nakamura, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The performance of an Arthrobacter viscosus culture to remove diethylketone from aqueous solutions was evaluated. The effect of initial concentration of diethylketone on the growth of the bacteria was evaluated for the range of concentration between 0 and 4.8 g/l, aiming to evaluate a possible toxicological effect. The maximum specific growth rate achieved is 0.221 h −1 at 1.6 g/l of initial diethylketone concentration, suggesting that for higher concentrations an inhibitory effect on the growth occurs. The removal percentages obtained were approximately 88%, for all the initial concentrations tested. The kinetic parameters were estimated using four growth kinetic models for biodegradation of organic compounds available in the literature. The experimental data found is well fitted by the Haldane model ( R 2  = 1) as compared to Monod model ( R 2  = 0.99), Powell ( R 2  = 0.82) and Loung model ( R 2  = 0.95). The biodegradation of diethylketone using concentrated biomass was studied for an initial diethylketone concentration ranging from 0.8–3.9 g/l in a batch with recirculation mode of operation. The biodegradation rate found followed the pseudo-second order kinetics and the resulting kinetic parameters are reported. The removal percentages obtained were approximately 100%, for all the initial concentrations tested, suggesting that the increment on the biomass concentration allows better results in terms of removal of diethylketone. This study showed that these bacteria are very effective for the removal of diethylketone from aqueous solutions. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9488-7 Authors Filomena Costa, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Cristina Quintelas, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Teresa Tavares, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Trichloroethylene (TCE) is extensively used in commercial applications, despite its risk to human health via soil and groundwater contamination. The stability of TCE, which is a useful characteristic for commercial application, makes it difficult to remove it from the environment. Numerous studies have demonstrated that TCE can be effectively removed from the environment using bioremediation. Pseudomonas putida F1 is capable of degrading TCE into less hazardous byproducts via the toluene dioxygenase pathway (TOD). Unfortunately, these bioremediation systems are not self-sustaining, as the degradation capacity declines over time. Fortunately, the replacement of metabolic co-factors is sufficient in many cases to maintain effective TCE degradation. Thus, monitoring systems must be developed to predict when TCE degradation rates are likely to decline. Herein, we show evidence that tod expression levels correlate with the ability of P. putida F1 to metabolize TCE in the presence of toluene. Furthermore, the presence of toluene improves the replication of P . putida F1, even when TCE is present at high concentration. These findings may be applied to real world applications to decide when the bioremediation system requires supplementation with aromatic substrates, in order to maintain maximum TCE removal capacity. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9544-y Authors Jianbo Liu, College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Sifang District, Qingdao, 266061 China Takashi Amemiya, Graduate School of Environment and Information Science, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501 Japan Qing Chang, Graduate School of Environment and Information Science, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501 Japan Yi Qian, College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Sifang District, Qingdao, 266061 China Kiminori Itoh, Graduate School of Engineering, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Molasses melanoidin (MM) is a major pollutant in biomethanated distillery spent wash (BMDS) due to its recalcitrant properties. The 75% colour and 71% COD of MM (1,000 ppm) were reduced with developed bacterial consortium comprising Proteus mirabilis (IITRM5; FJ581028), Bacillus sp. (IITRM7; FJ581030), Raoultella planticola (IITRM15; GU329705) and Enterobacter sakazakii (IITRM16, FJ581031) in the ratio of 4:3:2:1 within 10 days at optimized nutrient. Bacterial consortium showed manganese peroxidase and laccase activity during MM decolourisation. The dominant growth of R . planticola and E . sakazakii was noted in consortium during MM decolourisation. The comparative GC–MS analysis of extracted compounds of control and degraded samples showed that most of the compounds present in control were completely utilized by bacterial consortium along with production of some metabolites. The developed bacterial consortium could be a tool for the decolourisation and degradation of melanoidin containing BMDS. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10532-012-9537-x Authors Sangeeta Yadav, Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University (A Central University), Vidya Vihar, Raebareli Road, Lucknow, 226025 Uttar Pradesh, India Ram Chandra, Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University (A Central University), Vidya Vihar, Raebareli Road, Lucknow, 226025 Uttar Pradesh, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The capacity of an anaerobic sediment to achieve the simultaneous biodegradation of phenol and carbon tetrachloride (CT) was evaluated, using humic acids (HA) as redox mediator. The presence of HA in sediment incubations increased the rate of biodegradation of phenol and the rate of dehalogenation (2.5-fold) of CT compared to controls lacking HA. Further experiments revealed that the electron-accepting capacity of HA derived from different organic-rich environments was not associated with their reducing capacity to achieve CT dechlorination. The collected kinetic data suggest that the reduction of CT by reduced HA was the rate-limiting step during the simultaneous biodegradation of phenol and CT. To our knowledge, the present study constitutes the first demonstration of the simultaneous biodegradation of two priority pollutants mediated by HA. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9539-8 Authors Claudia M. Martínez, División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª Sección, 78216 San Luis Potosí, SLP, Mexico Luis H. Alvarez, División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª Sección, 78216 San Luis Potosí, SLP, Mexico Francisco J. Cervantes, División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª Sección, 78216 San Luis Potosí, SLP, Mexico Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Assessing in situ microbial abilities of soils to degrade pesticides is of great interest giving insight in soil filtering capability, which is a key ecosystem function limiting pollution of groundwater. Quantification of pesticide-degrading gene expression by reverse transcription quantitative PCR (RT-qPCR) was tested as a suitable indicator to monitor pesticide biodegradation performances in soil. RNA extraction protocol was optimized to enhance the yield and quality of RNA recovered from soil samples to perform RT-qPCR assays. As a model, the activity of atrazine-degrading communities was monitored using RT-qPCRs to estimate the level of expression of atzD in five agricultural soils showing different atrazine mineralization abilities. Interestingly, the relative abundance of atzD mRNA copy numbers was positively correlated to the maximum rate and to the maximal amount of atrazine mineralized. Our findings indicate that the quantification of pesticide-degrading gene expression may be suitable to assess biodegradation performance in soil and monitor natural attenuation of pesticide. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9574-5 Authors Cécile Monard, UMR CNRS 6553 ‘EcoBio’—IFR2116/FR90 CAREN, Université de Rennes 1, 263 Avenue du Général Leclerc, Bat 14B, 35042 Rennes Cedex, France Fabrice Martin-Laurent, UMR 1347 Agroecologie, AgroSup/INRA/Université de Bourgogne, 17 rue Sully, BP 86510, 21065 Dijon Cedex, France Oscar Lima, UMR CNRS 6553 ‘EcoBio’—IFR2116/FR90 CAREN, Université de Rennes 1, 263 Avenue du Général Leclerc, Bat 14B, 35042 Rennes Cedex, France Marion Devers-Lamrani, UMR 1347 Agroecologie, AgroSup/INRA/Université de Bourgogne, 17 rue Sully, BP 86510, 21065 Dijon Cedex, France Françoise Binet, UMR CNRS 6553 ‘EcoBio’—IFR2116/FR90 CAREN, Université de Rennes 1, 263 Avenue du Général Leclerc, Bat 14B, 35042 Rennes Cedex, France Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Plasmid-mediated bioaugmentation was demonstrated using sequencing batch reactors (SBRs) for enhancing 2,4-dichlorophenoxyacetic acid (2,4-D) removal by introducing Cupriavidus necator JMP134 and Escherichia coli HB101 harboring 2,4-D-degrading plasmid pJP4. C. necator JMP134(pJP4) can mineralize and grow on 2,4-D, while E. coli HB101(pJP4) cannot assimilate 2,4-D because it lacks the chromosomal genes to degrade the intermediates. The SBR with C. necator JMP134(pJP4) showed 100 % removal against 200 mg/l of 2,4-D just after its introduction, after which 2,4-D removal dropped to 0 % on day 7 with the decline in viability of the introduced strain. The SBR with E. coli HB101(pJP4) showed low 2,4-D removal, i.e., below 10 %, until day 7. Transconjugant strains of Pseudomonas and Achromobacter isolated on day 7 could not grow on 2,4-D. Both SBRs started removing 2,4-D at 100 % after day 16 with the appearance of 2,4-D-degrading transconjugants belonging to Achromobacter , Burkholderia , Cupriavidus , and Pandoraea . After the influent 2,4-D concentration was increased to 500 mg/l on day 65, the SBR with E. coli HB101(pJP4) maintained stable 2,4-D removal of more than 95 %. Although the SBR with C. necator JMP134(pJP4) showed a temporal depression of 2,4-D removal of 65 % on day 76, almost 100 % removal was achieved thereafter. During this period, transconjugants isolated from both SBRs were mainly Achromobacter with high 2,4-D-degrading capability. In conclusion, plasmid-mediated bioaugmentation can enhance the degradation capability of activated sludge regardless of the survival of introduced strains and their 2,4-D degradation capacity. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9591-4 Authors Hirofumi Tsutsui, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Yasutaka Anami, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Masami Matsuda, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Kurumi Hashimoto, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Daisuke Inoue, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Kazunari Sei, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Satoshi Soda, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Michihiko Ike, Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The effectiveness of many bioremediation systems for PAH-contaminated soil may be constrained by low contaminant bioaccessibility due to limited aqueous solubility or large sorption capacity. Information on the extent to which PAHs can be readily biodegraded is of vital importance in the decision whether or not to remediate a contaminated soil. In the present study the rate-limiting factors in methyl-β-cyclodextrin (MCD)-enhanced bioremediation of PAH-contaminated soil were evaluated. MCD amendment at 10 % (w/w) combined with inoculation with the PAH-degrading bacterium Paracoccus sp. strain HPD-2 produced maximum removal of total PAHs of up to 35 %. The desorption of PAHs from contaminated soil was determined before and after 32 weeks of bioremediation. 10 % (w/w) MCD amendment (M2) increased the Tenax extraction of total PAHs from 12 to 30 % and promoted degradation by up to 26 % compared to 6 % in the control. However, the percentage of Tenax extraction for total PAHs was much larger than that of degradation. Thus, in the control and M2 treatment it is likely that during the initial phase the bioaccessibility of PAHs is high and biodegradation rates may be limited by microbial processes. On the other hand, when the soil was inoculated with the PAH-degrading bacterium (CKB and MB2), the slowly and very slowly desorbing fractions ( F sl and F vl ) became larger and the rate constants of slow and very slow desorption ( k sl and k vl ) became extremely small after bioremediation, suggesting that desorption is likely rate limiting during the second, slow phase of biotransformation. These results have practical implications for site risk assessment and cleanup strategies. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9593-2 Authors Mingming Sun, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Yongming Luo, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Ying Teng, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Peter Christie, Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX UK Zhongjun Jia, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Zhengao Li, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    This review focuses on ligninolytic fungi, soil bacteria, plants and root exudates in the degradation and solubilisation of low grade and waste coal and the interaction between these mutualistic biocatalysts. Coal represents a considerable portion of the total global fossil fuel reserve and continued demand for, and supply of this resource generates vast quantities of spoil and low grade waste. Large scale bioremediation technologies for the beneficiation of waste coal have unfortunately not yet been realised despite the many discoveries of microorganisms capable of lignite, lignin, and humic acid breakdown. Even so, solubilisation and depolymerization of low grade coal appears to involve either ligninolytic enzyme action or the production of alkaline substances or both. While the precise mechanism of coal biosolubilisation is unclear, a model for the phyto-biodegradation of low rank coal by mutualistic interaction between ligninolytic microorganisms and higher plants is proposed. Based on accumulated evidence this model suggests that solubilisation and degradation of lignite and waste coals commences upon plant root exudate and ligninolytic microorganism interaction, which is mutualistic, and includes soil bacteria and both mycorrhizal and non-mycorrhizal fungi. It is envisaged that this model and its further elaboration will aid in the development of functional technologies for commercial bioremediation of coal mine spoils, contribute to soil formation, and the overall biogeochemistry of organic carbon in the global ecosystem. Content Type Journal Article Category Review Article Pages 1-14 DOI 10.1007/s10532-012-9594-1 Authors Lerato M. Sekhohola, Institute for Environmental Biotechnology, Rhodes University, PO Box 94, Grahamstown, 6140 South Africa Eric E. Igbinigie, Institute for Environmental Biotechnology, Rhodes University, PO Box 94, Grahamstown, 6140 South Africa A. Keith Cowan, Institute for Environmental Biotechnology, Rhodes University, PO Box 94, Grahamstown, 6140 South Africa Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Field experiments were conducted to assess the potential for anaerobic biostimulation to enhance BTEX biodegradation under fermentative methanogenic conditions in groundwater impacted by a biodiesel blend (B20, consisting of 20 % v/v biodiesel and 80 % v/v diesel). B20 (100 L) was released at each of two plots through an area of 1 m 2 that was excavated down to the water table, 1.6 m below ground surface. One release was biostimulated with ammonium acetate, which was added weekly through injection wells near the source zone over 15 months. The other release was not biostimulated and served as a baseline control simulating natural attenuation. Ammonium acetate addition stimulated the development of strongly anaerobic conditions, as indicated by near-saturation methane concentrations. BTEX removal began within 8 months in the biostimulated source zone, but not in the natural attenuation control, where BTEX concentrations were still increasing (due to source dissolution) 2 years after the release. Phylogenetic analysis using quantitative PCR indicated an increase in concentration and relative abundance of Archaea (Crenarchaeota and Euryarchaeota), Geobacteraceae ( Geobacter and Pelobacter spp.) and sulfate-reducing bacteria ( Desulfovibrio , Desulfomicrobium , Desulfuromusa , and Desulfuromonas ) in the biostimulated plot relative to the control. Apparently, biostimulation fortuitously enhanced the growth of putative anaerobic BTEX degraders and associated commensal microorganisms that consume acetate and H 2 , and enhance the thermodynamic feasibility of BTEX fermentation. This is the first field study to suggest that anaerobic-methanogenic biostimulation could enhance source zone bioremediation of groundwater aquifers impacted by biodiesel blends. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9589-y Authors Débora Toledo Ramos, Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil Márcio Luis Busi da Silva, EMBRAPA, BR153 Km 110, P.O. Box 21, Concórdia, SC 89700-000, Brazil Helen Simone Chiaranda, Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil Pedro J. J. Alvarez, Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA Henry Xavier Corseuil, Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Pseudoxanthomonas sp. RN402 was capable of degrading diesel, crude oil, n -tetradecane and n -hexadecane. The RN402 cells were immobilized on the surface of high-density polyethylene plastic pellets at a maximum cell density of 10 8 most probable number (MPN) g −1 of plastic pellets. The immobilized cells not only showed a higher efficacy of diesel oil removal than free cells but could also degrade higher concentrations of diesel oil. The rate of diesel oil removal by immobilized RN402 cells in liquid culture was 1,050 mg l −1  day −1 . Moreover, the immobilized cells could maintain high efficacy and viability throughout 70 cycles of bioremedial treatment of diesel-contaminated water. The stability of diesel oil degradation in the immobilized cells resulted from the ability of living RN402 cells to attach to material surfaces by biofilm formation, as was shown by CLSM imaging. These characteristics of the immobilized RN402 cells, including high degradative efficacy, stability and flotation, make them suitable for the purpose of continuous wastewater bioremediation. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9596-z Authors Wannarak Nopcharoenkul, Inter-Department of Environmental Science, Graduate School, Chulalongkorn University, Bangkok, 10330 Thailand Parichat Netsakulnee, Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330 Thailand Onruthai Pinyakong, Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330 Thailand Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Stimulation of native microbial populations in soil by the addition of small amounts of secondary carbon sources (cosubstrates) and its effect on the degradation and theoretical mineralization of DDT [l,l,l-trichloro-2,2-bis( p -chlorophenyl)ethane] and its main metabolites, DDD and DDE, were evaluated. Microbial activity in soil polluted with DDT, DDE and DDD was increased by the presence of phenol, hexane and toluene as cosubstrates. The consumption of DDT was increased from 23 % in a control (without cosubstrate) to 67, 59 and 56 % in the presence of phenol, hexane and toluene, respectively. DDE was completely removed in all cases, and DDD removal was enhanced from 67 % in the control to ~86 % with all substrates tested, except for acetic acid and glucose substrates. In the latter cases, DDD removal was either inhibited or unchanged from the control. The optimal amount of added cosubstrate was observed to be between 0.64 and 2.6 mg C \text g - 1 \text dry soil . The CO 2 produced was higher than the theoretical amount for complete cosubstrate mineralization indicating possible mineralization of DDT and its metabolites. Bacterial communities were evaluated by denaturing gradient gel electrophoresis, which indicated that native soil and the untreated control presented a low bacterial diversity. The detected bacteria were related to soil microorganisms and microorganisms with known biodegradative potential. In the presence of toluene a bacterium related to Azoarcus , a genus that includes species capable of growing at the expense of aromatic compounds such as toluene and halobenzoates under denitrifying conditions, was detected. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9578-1 Authors Irmene Ortíz, Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Hidalgo, Delegación Álvaro Obregón, 01120 Mexico, DF, Mexico Antonio Velasco, Centro Nacional de Investigación y Capacitación Ambiental, Instituto Nacional de Ecología, Mexico, DF, Mexico Sylvie Le Borgne, Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Hidalgo, Delegación Álvaro Obregón, 01120 Mexico, DF, Mexico Sergio Revah, Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Hidalgo, Delegación Álvaro Obregón, 01120 Mexico, DF, Mexico Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A comprehensive study on the effects of different carbon sources during the bacterial enrichment on the removal performances of benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds when present as a mixture was conducted. Batch BTEX removal kinetic experiments were performed using cultures enriched with individual BTEX compounds or BTEX as a mixture or benzoate alone or benzoate–BTEX mixture. An integrated Monod-type non-linear model was developed and a ratio between maximum growth rate ( μ max ) and half saturation constant (K s ) was used to fit the non-linear model. A higher μ max /K s indicates a higher affinity to degrade BTEX compounds. Complete removal of BTEX mixture was observed by all the enriched cultures; however, the removal rates for individual compounds varied. Degradation rate and the type of removal kinetics were found to be dependent on the type of carbon source during the enrichment. Cultures enriched on toluene and those enriched on BTEX mixture were found to have the greatest μ max /K s and cultures enriched on benzoate had the least μ max /K s . Removal performances of the cultures enriched on all different carbon sources, including the ones enriched on benzoate or benzoate–BTEX mixture were also improved during a second exposure to BTEX. A molecular analysis showed that after each exposure to the BTEX mixture, the cultures enriched on benzoate and those enriched on benzoate–BTEX mixture had increased similarities to the culture enriched on BTEX mixture. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10532-012-9586-1 Authors Murthy Kasi, Department of Civil Engineering, North Dakota State University, Fargo, ND 58105, USA Tanush Wadhawan, Department of Civil Engineering, North Dakota State University, Fargo, ND 58105, USA John McEvoy, Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND 58105, USA G. Padmanabhan, Department of Civil Engineering, North Dakota State University, Fargo, ND 58105, USA Eakalak Khan, Department of Civil Engineering, North Dakota State University, Fargo, ND 58105, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Over the past few decades significant progress has been made in research on DDT degradation in the environment. This review is an update of some of the recent studies on the degradation and biodegradation pathways of DDT and its metabolites, particularly in soils. The latest reports on human toxicity shows that DDT intake is still occurring even in countries that banned its use decades ago. Ageing, sequestration and formation of toxic metabolites during the degradation processes pose environmental challenges and result in difficulties in bioremediation of DDT contaminated soils. Degradation enhancement strategies such as the addition of chelators, low molecular organic acids, co-solvent washing and the use of sodium and seaweeds as ameliorant have been studied to accelerate degradation. This review describes and discusses the recent challenges and degradation enhancement strategies for DDT degradation by potentially cost effective procedures based on bioremediation. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10532-012-9575-4 Authors Simi Sudharshan, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA, Australia Ravi Naidu, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA, Australia Megharaj Mallavarapu, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA, Australia Nanthi Bolan, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A sequencing batch reactor was employed to treat the acrylic fiber wastewater. The dissolved oxygen and mixed liquor suspended solids were 2–3 and 3,500–4,000 mg/L, respectively. The results showed ammonium oxidizing bacteria (AOB) had superior growth rate at high temperature than nitrite oxidizing bacteria (NOB). Partial nitrification could be obtained with the temperature of 28 °C. When the pH value was 8.5, the nitrite-N accumulation efficiency was 82 %. The combined inhibitions of high pH and free ammonium to NOB devoted to the nitrite-N buildup. Hydraulic retention time (HRT) was a key factor in partial nitrification control, and the optimal HRT was 20 h for nitrite-N buildup in acrylic fiber wastewater treatment. The ammonium oxidation was almost complete and the transformation from nitrite to nitrate could be avoided. AOB and NOB accounted for 2.9 and 4.7 %, respectively, corresponding to the pH of 7.0. When the pH was 8.5, they were 6.7 and 0.9 %, respectively. AOB dominated nitrifying bacteria, and NOB was actually washed out from the system. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9599-9 Authors Jin Li, School of Chemical and Environmental Engineering, Qingdao University, Qingdao, People’s Republic of China Deshuang Yu, School of Chemical and Environmental Engineering, Qingdao University, Qingdao, People’s Republic of China Peiyu Zhang, School of Chemical and Environmental Engineering, Qingdao University, Qingdao, People’s Republic of China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In biological nitrogen removal, application of the autotrophic anammox process is gaining ground worldwide. Although this field has been widely researched in last years, some aspects as the accelerating effect of putative intermediates (mainly N 2 H 4 and NH 2 OH) need more specific investigation. In the current study, experiments in a moving bed biofilm reactor (MBBR) and batch tests were performed to evaluate the optimum concentrations of anammox process intermediates that accelerate the autotrophic nitrogen removal and mitigate a decrease in the anammox bacteria activity using anammox (anaerobic ammonium oxidation) biomass enriched on ring-shaped biofilm carriers. Anammox biomass was previously grown on blank biofilm carriers for 450 days at moderate temperature 26.0 (±0.5) °C by using sludge reject water as seeding material. FISH analysis revealed that anammox microorganisms were located in clusters in the biofilm. With addition of 1.27 and 1.31 mg N L −1 of each NH 2 OH and N 2 H 4 , respectively, into the MBBR total nitrogen (TN) removal efficiency was rapidly restored after inhibitions by NO 2 − . Various combinations of N 2 H 4 , NH 2 OH, NH 4 + , and NO 2 − were used as batch substrates. The highest total nitrogen (TN) removal rate with the optimum N 2 H 4 concentration (4.38 mg N L −1 ) present in these batches was 5.43 mg N g −1 TSS h −1 , whereas equimolar concentrations of N 2 H 4 and NH 2 OH added together showed lower TN removal rates. Intermediates could be applied in practice to contribute to the recovery of inhibition-damaged wastewater treatment facilities using anammox technology. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9549-6 Authors Ivar Zekker, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Kristel Kroon, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Ergo Rikmann, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Toomas Tenno, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Martin Tomingas, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Priit Vabamäe, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Siegfried E. Vlaeminck, Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium Taavo Tenno, Institute of Chemistry, University of Tartu, 14a Ravila St., 50411 Tartu, Estonia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Because benzene, toluene, ethylbenzene, and xylenes (BTEX) and ethanol are important contaminants present in Brazilian gasoline, it is essential to develop technology that can be used in the bioremediation of gasoline-contaminated aquifers. This paper evaluates the performance of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor fed with water containing gasoline constituents under denitrifying conditions. Two HAIB reactors filled with polyurethane foam matrices (5 mm cubes, 23 kg/m 3 density and 95 % porosity) for biomass attachment were assayed. The reactor fed with synthetic substrate containing protein, carbohydrates, sodium bicarbonate and BTEX solution in ethanol, at an Hydraulic retention time (HRT) of 13.5 h, presented hydrocarbon removal efficiencies of 99 % at the following initial concentrations: benzene 6.7 mg/L, toluene 4.9 mg/L, m -xylene and p -xylene 7.2 mg/L, ethylbenzene 3.7 mg/L, and nitrate 60 mg N/L. The HAIB reactor fed with gasoline-contaminated water at an HRT of 20 h showed hydrocarbon removal efficiencies of 96 % at the following initial concentrations: benzene, 4.9 mg/L; toluene, 7.2 mg/L; m -xylene, 3.7 mg/L; and nitrate 400 mg N/L. Microbiological observations along the length of the HAIB reactor fed with gasoline-contaminated water confirmed that in the first segment of the reactor, denitrifying metabolism predominated, whereas from the first sampling port on, the metabolism observed was predominantly methanogenic. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9585-2 Authors Rogers Ribeiro, Laboratório de Biotecnologia Ambiental, Departamento de Engenharia de Alimentos, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Av. Duque de Caxias norte, 225, Pirassununga, SP 13635-900, Brazil Ivana Ribeiro de Nardi, Centro Universitário Central Paulista, São Carlos, Brazil Bruna Soares Fernandes, Laboratório de Processos Biológicos, Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo, São Carlos, Brazil Eugenio Foresti, Laboratório de Processos Biológicos, Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo, São Carlos, Brazil Marcelo Zaiat, Laboratório de Processos Biológicos, Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo, São Carlos, Brazil Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A genetically engineered microorganism (GEM) capable of simultaneously degrading organophosphate and organochlorine pesticides was constructed for the first time by display of organophosphorus hydrolase (OPH) on the cell surface of a hexachlorocyclohexane (HCH)-degrading Sphingobium japonicum UT26. The GEM could potentially be used for removing the two classes of pesticides that may be present in mixtures at contaminated sites. A surface anchor system derived from the truncated ice nucleation protein (INPNC) from Pseudomonas syringae was used to target OPH onto the cell surface of UT26, reducing the potential substrate uptake limitation. The surface localization of INPNC–OPH fusion was verified by cell fractionation, western blot, proteinase accessibility, and immunofluorescence microscopy. Furthermore, the functionality of the surface-exposed OPH was demonstrated by OPH activity assays. Surface display of INPNC–OPH fusion (82 kDa) neither inhibited cell growth nor affected cell viability. The engineered UT26 could degrade parathion as well as γ-HCH rapidly in minimal salt medium. The removal of parathion and γ-HCH by engineered UT26 in sterile and non-sterile soil was also studied. In both soil samples, a mixture of parathion (100 mg kg −1 ) and γ-HCH (10 mg kg −1 ) could be degraded completely within 15 days. Soil treatment results indicated that the engineered UT26 is a promising multifunctional bacterium that could be used for the bioremediation of multiple pesticide-contaminated environments. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9587-0 Authors Xiangyu Cao, School of Life Science, Liaoning University, Shenyang, 110036 China Chao Yang, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071 China Ruihua Liu, State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Tianjin, 300071 China Qiang Li, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071 China Wei Zhang, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071 China Jianli Liu, School of Life Science, Liaoning University, Shenyang, 110036 China Cunjiang Song, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071 China Chuanling Qiao, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China Ashok Mulchandani, Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    This study evaluated the potential of monitored natural attenuation (MNA) as a remedial option for groundwater at a long-term petroleum hydrocarbon contaminated site in Australia. Source characterization revealed that total petroleum hydrocarbons (TPH) as the major contaminant of concern in the smear zone and groundwater. Multiple lines of evidence involving the geochemical parameters, microbiological analysis, data modelling and compound-specific stable carbon isotope analysis all demonstrated natural attenuation of hydrocarbons occurring in the groundwater via intrinsic biodegradation. Groundwater monitoring data by Mann–Kendall trend analysis using properly designed and installed groundwater monitoring wells shows the plume is stable and neither expanding nor shrinking. The reason for stable plume is due to the presence of both active source and natural attenuation on the edge of the plume. Assuming no retardation and no degradation the contaminated plume would have travelled a distance of 1,096 m (best case) to 11,496 m (worst case) in 30 years. However, the plume was extended only up to about 170 m from its source. The results of these investigations provide strong scientific evidence for natural attenuation of TPH in this contaminated aquifer. Therefore, MNA can be applied as a defensible management option for this site following significant reduction of TPH in the source zone. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10532-012-9580-7 Authors Ravi Naidu, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia Subhas Nandy, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia Mallavarapu Megharaj, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia R. P. Kumar, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia Sreenivasulu Chadalavada, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia Zuliang Chen, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA 5095, Australia Mark Bowman, Department of Defence, Canberra, ACT 2600, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    This unique study describes how Aspergillus japonicus , Penicillium brocae and Purpureocillium lilacinum , three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n -hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5 % w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15–0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9584-3 Authors S. Pradeep, Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Malappuram, Kerala 673 635, India P. Faseela, Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Malappuram, Kerala 673 635, India M. K. Sarath Josh, Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Malappuram, Kerala 673 635, India S. Balachandran, Department of Chemistry, Mahatma Gandhi College, Thiruvananthapuram, Kerala 695 004, India R. Sudha Devi, Department of Chemistry, Mahatma Gandhi College, Thiruvananthapuram, Kerala 695 004, India Sailas Benjamin, Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Malappuram, Kerala 673 635, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Cultivation of the biofuel plant, hybrid giant Napier grass (HGN), in saline soil was investigated in a greenhouse study. The results show that HGN is a salt tolerant plant which can flourish in saline soil and product a large amount of biomass. The extensively developed fibrous root system of HGN plays a significant role in the uptake of sodium from saline soil so that both soil salinity and pH are reduced. Fibrous roots of HGN are well distributed in the soil below the surface, where the metabolism of the root system produces a gradient at the depth between 10 and 20 cm in soil salinity, pH and organic content. The degradation of the HGN by the biota within the soil results in an increase in nutrients and improved soil quality. The experimental results suggest that HGN adapts to saline soil, which is promising for phytoremediation of such soils. Additional advantages of HGN include the large biomass produced which can be used for renewable energy generation. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9583-4 Authors Chongjian Ma, College of Agricultural Science and Engineering, Shaoguan University, Shaoguan, 512005 Guangdong, People’s Republic of China Ravi Naidu, CRC CARE, P.O. Box 486, Salisbury South, SA 5106, Australia Faguang Liu, College of Agricultural Science and Engineering, Shaoguan University, Shaoguan, 512005 Guangdong, People’s Republic of China Changhua Lin, College of Agricultural Science and Engineering, Shaoguan University, Shaoguan, 512005 Guangdong, People’s Republic of China Hui Ming, CRC CARE, P.O. Box 486, Salisbury South, SA 5106, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Bioremediation of polyaromatic hydrocarbons (PAH) contaminated soils in the presence of heavy metals have proved to be difficult and often challenging due to the ability of toxic metals to inhibit PAH degradation by bacteria. In this study, a mixed bacterial culture designated as consortium-5 was isolated from a former manufactured gas plant (MGP) site. The ability of this consortium to utilise HMW PAHs such as pyrene and BaP as a sole carbon source in the presence of toxic metal Cd was demonstrated. Furthermore, this consortium has proven to be effective in degradation of HMW PAHs even from the real long term contaminated MGP soil. Thus, the results of this study demonstrate the great potential of this consortium for field scale bioremediation of PAHs in long term mix contaminated soils such as MGP sites. To our knowledge this is the first study to isolate and characterize metal tolerant HMW PAH degrading bacterial consortium which shows great potential in bioremediation of mixed contaminated soils such as MGP. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10532-012-9572-7 Authors Palanisami Thavamani, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA 5095, Australia Mallavarapu Megharaj, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA 5095, Australia Ravi Naidu, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA 5095, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Methylmercury (MeHg) is one of the most dangerous heavy metal for living organisms that may be found in environment. Given the crescent industrialization of Brazil and considering that mercury is a residue of several industrial processes, there is an increasing need to encounter and develop remediation approaches of mercury contaminated sites. The aim of this study was to isolate and characterize methylmercury resistant bacteria from soils and sludge sewage from Rio Grande do Sul, Brazil. Sixteen bacteria were isolated from these contaminated sites and some isolates were highly resistant to methylmercury (〉8.7 μM). All the isolates were identified by 16S rDNA. Pseudomonas putida V1 was able to volatilize approximately 90 % of methylmercury added to growth media and to resist to copper, lead, nickel, chromate, zinc, cobalt, manganese and barium. In the presence of high concentrations of methylmercury (12 μM), cell growth was limited, but P. putida V1 was still able to remove up to 29 % of this compound from culture medium. This bacterium removed an average of 77 % of methylmercury from culture medium with pH in the range 4.0–6.0. In addition, methylmercury was efficiently removed (〉80 %) in temperature of 21–25 °C. Polymerase chain reactions indicated the presence of mer A but not mer B in P. putida V1. The growth and ability of P. putida V1 to remove methylmercury in a wide range of pH (4.0 and 8.0) and temperature (10–35 °C), its tolerance to other heavy metals and ability to grow in the presence of up to 11.5 μM of methylmercury, suggest this strain as a new potential resource for degrading methylmercury contaminated sites. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10532-012-9588-z Authors Lucélia Cabral, Department of Soil Science, Federal University of Rio Grande do Sul, UFRGS, Avenida Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil Patrícia Giovanella, Department of Microbiology, Instituto de Ciências Básicas da Saúde, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, Porto Alegre, RS 90050-170, Brazil Clésio Gianello, Department of Soil Science, Federal University of Rio Grande do Sul, UFRGS, Avenida Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil Fátima Menezes Bento, Department of Microbiology, Instituto de Ciências Básicas da Saúde, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, Porto Alegre, RS 90050-170, Brazil Robson Andreazza, Centro de Engenharias (CENG), Federal University of Pelotas, Av. Almirante Barroso, 1734. Centro., Pelotas, RS 96010-280, Brazil Flávio Anastácio Oliveira Camargo, Department of Soil Science, Federal University of Rio Grande do Sul, UFRGS, Avenida Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description: Cleaning contaminated environment: a growing challenge Content Type Journal Article Category Editorial Pages 1-2 DOI 10.1007/s10532-012-9590-5 Authors Brajesh K. Singh, University of Western Sydney, Penrith, NSW, Australia Ravi Naidu, Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10532-012-9562-9 Authors Raquel Almeida, CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal Ana P. Mucha, CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal Catarina Teixeira, CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal Adriano A. Bordalo, CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal C. Marisa R. Almeida, CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Thiodiglycol (TDG) is both the precursor for chemical synthesis of mustard gas and the product of mustard gas hydrolysis. TDG can also react with intermediates of mustard gas degradation to form more toxic and/or persistent aggregates, or reverse the pathway of mustard gas degradation. The persistence of TDG have been observed in soils and in the groundwater at sites contaminated by mustard gas 60 years ago. The biotransformation of TDG has been demonstrated in three soils not previously exposed to the chemical. TDG biotransformation occurred via the oxidative pathway with an optimum rate at pH 8.25. In contrast with bacteria isolated from historically contaminated soil, which could degrade TDG individually, a consortium of three bacterial strains isolated from the soil never contaminated by mustard gas was able to grow on TDG in minimal medium and in hydrolysate derived from an historical mustard gas bomb. Exposure to TDG had little impacts on the soil microbial physiology or on community structure. Therefore, the persistency of TDG in soils historically contaminated by mustard gas might be attributed to the toxicity of mustard gas to microorganisms and the impact to soil chemistry during the hydrolysis. TDG biodegradation may form part of a remediation strategy for mustard gas contaminated sites, and may be enhanced by pH adjustment and aeration. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9564-7 Authors Hong Li, Natural Environmental Research Council, Centre for Ecology and Hydrology, Mansfield Road, Oxford, OX1 3SR UK Robert Muir, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wilts SP4 0JQ, UK Neil R. McFarlane, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wilts SP4 0JQ, UK Richard J. Soilleux, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wilts SP4 0JQ, UK Xiaohong Yu, Natural Environmental Research Council, Centre for Ecology and Hydrology, Mansfield Road, Oxford, OX1 3SR UK Ian P. Thompson, Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ UK Simon A. Jackman, Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR UK Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The biodegradation of heptadecane in five sand columns was modeled using a multiplicative Monod approach. Each column contained 1.0 kg of sand and 2 g of heptadecane, and was supplied with an artificial seawater solution containing nutrients at a flow rate that resulted in unsaturated flow through the column. All nutrients were provided in excess with the exception of nitrate whose influent concentration was 0.1, 0.5, 1.0, 2.5, or 5.0 mg N/L. The experiment was run around 912 h until no measurable oxygen consumption or CO 2 production was observed. The residual mass of heptadecane was measured at the end of the experiments and the biodegradation was monitored based on oxygen consumption and CO 2 production. Biodegradation kinetic parameters were estimated by fitting the model to experimental data of oxygen, CO 2 , and residual mass of heptadecane obtained from the two columns having influent nitrate–N concentration of 0.5 and 2.5 mg/L. Noting that the oxygen and CO 2 measurements leveled off at around 450 h, we fitted the model to these data for that range. The estimated parameters fell in within the range reported in the literature. In particular, the half-saturation constant for nitrate utilization,  K \text N , was estimated to be 0.45 mg N/L, and the yield coefficient was found to be 0.15 mg biomass/mg heptadecane. Using these values, the rest of experimental data from the five columns was predicted, and the model agreed with the observations. There were some consistent discrepancies at large times between the model simulation and observed data in the cases with higher nitrate concentration. One plausible explanation for these differences could be limitation of biodegradation by reduction of the heptadecane–water interfacial area in these columns while the model uses a constant interfacial area. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9566-5 Authors Xiaolong Geng, Department of Civil and Environmental Engineering, Center for Natural Resources Development and Protection, New Jersey Institute of Technology, Newark, NJ 07102, USA Michel C. Boufadel, Department of Civil and Environmental Engineering, Center for Natural Resources Development and Protection, New Jersey Institute of Technology, Newark, NJ 07102, USA Brian Wrenn, Department of Civil and Environmental Engineering, Center for Natural Resources Development and Protection, New Jersey Institute of Technology, Newark, NJ 07102, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In order to elucidate the capability of biomass developed in membrane bioreactors (MBR) to degrade and sorb emerging micropollutants, biodegradation (k biol ) and sorption (k sor ) kinetic constants as well as solid–liquid partition coefficients (K d ) of 13 selected pharmaceutical and personal care products (PPCPs) were determined with MBR heterotrophic biomass adding a pulse (100 ppb of each compound) and following the liquid and solid phase concentrations over time. The results obtained were compared to literature data referring to conventional activated sludge (CAS) systems. Two experiments were performed: one in the MBR itself and the second one in a batch reactor with the same type and concentration of biomass as in the MBR. Overall, both biodegradation and sorption coefficients were in the same range as previously reported by other studies in CAS systems, indicating that MBR biomass does not show better capabilities for the biological degradation and/or sorption of PPCPs compared to the biomass developed in CAS reactors. Therefore, the higher PPCPs removal efficiencies found in MBRs are explained by the high biomass concentrations obtained at the long sludge retention times at which this type of reactors are usually operated. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10532-012-9568-3 Authors Eduardo Fernandez-Fontaina, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain Ines Pinho, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain Marta Carballa, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain Francisco Omil, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain Juan M. Lema, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A new arsenite-oxidizing bacterium was isolated from a low arsenic-containing (8.8 mg kg −1 ) soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Stenotrophomonas panacihumi . Batch experiment results showed that the strain completely oxidized 500 μM of arsenite to arsenate within 12 h of incubation in a minimal salts medium. The optimum initial pH range for arsenite oxidation was 5–7. The strain was found to tolerate as high as 60 mM arsenite in culture media. The arsenite oxidase gene was amplified by PCR with degenerate primers. The deduced amino acid sequence showed the highest identity (69.1 %) with the molybdenum containing large subunit of arsenite oxidase derived from Bosea sp. Furthermore the amino acids involved in binding the substrate arsenite, were conserved with the arsenite oxidases of other arsenite oxidizing bacteria such as Alcaligenes feacalis and Herminnimonas arsenicoxydans . To our knowledge, this study constitutes the first report on arsenite oxidation using Stenotrophomonas sp. and the strain has great potential for application in arsenic remediation of contaminated water. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9567-4 Authors Md. Mezbaul Bahar, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Building X, Room X2-03, Mawson Lakes Boulevard, Mawson Lakes, SA 5095, Australia Mallavarapu Megharaj, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Building X, Room X2-03, Mawson Lakes Boulevard, Mawson Lakes, SA 5095, Australia Ravi Naidu, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Building X, Room X2-03, Mawson Lakes Boulevard, Mawson Lakes, SA 5095, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this study, a number of slurry-phase strategies were trialled over a 42 day period in order to determine the efficacy of bioremediation for long-term hydrocarbon-contaminated soil (145 g kg −1 C 10 –C 40 ). The addition of activated sludge and nutrients to slurries (bioaugmentation) resulted in enhanced hydrocarbon removal (51.6 ± 8.5 %) compared to treatments receiving only nutrients (enhanced natural attenuation [ENA]; 41.3 ± 6.4 %) or no amendments (natural attenuation; no significant hydrocarbon removal, P  〈 0.01). This data suggests that the microbial community in the activated sludge inoculum contributed to the enhanced removal of hydrocarbons in ENA slurries. Microbial diversity in slurries was monitored using DGGE with dominant bands excised and sequenced for identification. Applying the different bioremediation strategies resulted in the formation of four distinct community clusters associated with the activated sludge (inoculum), bioaugmentation strategy at day 0, bioaugmentation strategy at weeks 2–6 and slurries with autoclaved sludge and nutrient additions (bioaugmentation negative control). While hydrocarbon-degrading bacteria genera (e.g. Aquabacterium and Haliscomenobacter ) were associated with the hydrocarbon-contaminated soil, bioaugmentation of soil slurries with activated sludge resulted in the introduction of bacteria associated with hydrocarbon degradation ( Burkholderiales order and Klebsiella genera) which presumably contributed to the enhanced efficacy for this slurry strategy. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9563-8 Authors Arturo Aburto-Medina, School of Biological Sciences, Flinders University of South Australia, Adelaide, 5001 Australia Eric M. Adetutu, School of Biological Sciences, Flinders University of South Australia, Adelaide, 5001 Australia Sam Aleer, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Adelaide, SA 5095, Australia John Weber, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Adelaide, SA 5095, Australia Sayali S. Patil, School of Biological Sciences, Flinders University of South Australia, Adelaide, 5001 Australia Petra J. Sheppard, School of Biological Sciences, Flinders University of South Australia, Adelaide, 5001 Australia Andrew S. Ball, School of Biological Sciences, Flinders University of South Australia, Adelaide, 5001 Australia Albert L. Juhasz, Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Adelaide, SA 5095, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A plug-flow type anaerobic ammonium oxidation (anammox) reactor was developed using malt ceramics (MC) produced from carbonized spent grains as the biomass carriers for anammox sludge. Partial nitrified effluent of the filtrate from the sludge dehydrator of a brewery company was used as influent to a 20 L anammox reactor using MC. An average volumetric nitrogen removal rate (VNR) of 8.78 kg-N/m 3 /day was maintained stably for 76 days with 1 h of HRT. In a larger anammox reactor (400 L), an average VNR of 4.84 kg-N/m 3 /day could be maintained for 86 days during the treatment of low strength synthetic inorganic wastewater. As a result of bacterial community analysis for the 20 L anammox reactor, Asahi BRW1, probably originating from the wastewater collected at Asahi Breweries, was detected as the dominant anammox bacterium. These anammox reactors were characterized by a high NH 4 -N removal capacity for low strength wastewater with a short hydraulic retention time. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10532-012-9561-x Authors Hiroyuki Okamoto, Research & Development Laboratories for Sustainable Value Creation, Asahi Group Holdings, Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan Kimito Kawamura, Research & Development Laboratories for Sustainable Value Creation, Asahi Group Holdings, Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan Takashi Nishiyama, Department of Applied Life Science, Sojo University, 22-1, Ikeda 4-Chome, Kumamoto-shi, Kumamoto 860-0082, Japan Takao Fujii, Department of Applied Life Science, Sojo University, 22-1, Ikeda 4-Chome, Kumamoto-shi, Kumamoto 860-0082, Japan Kenji Furukawa, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A thermophilic bacterium capable of degrading acrylamide, AUT-01, was isolated from soil collected from a hot spring area in Montana, USA. The thermophilic strain grew with 0.2 % glucose as the sole carbon source and 1.4 mM acrylamide as the sole nitrogen source. The isolate AUT-01 was identified as Geobacillus thermoglucosidasius based on 16S rDNA sequence. An enzyme from the strain capable of transforming acrylamide to acrylic acid was purified by a series of chromatographic columns. The molecular weight of the enzyme was estimated to be 38 kDa by SDS-PAGE. The enzyme activity had pH and temperature optima of 6.2 and 70 ºC, respectively. The influence of different metals and amino acids on the ability of the purified protein to transform acrylamide to acrylic acid was evaluated. The gene from G. thermoglucosidasius encoding the acrylamidase was cloned, sequenced, and compared to aliphatic amidases from other bacterial strains. The G. thermoglucosidasius gene, amiE , encoded a 38 kDa, monomeric, heat-stable amidase that catalysed the cleavage of carbon–nitrogen bonds in acrylamide. Comparison of the amino acid sequence to other bacterial amidases revealed 99 and 82 % similarity to the amino acid sequences of Bacillus stearothermophilus and Pseudomonas aeruginosa , respectively. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9557-6 Authors Minseok Cha, Department of Bacteriology and Department of Food Science, University of Wisconsin-Madison, 1550 Linden Dr., Microbial Sciences Building, Madison, WI 53706, USA Glenn H. Chambliss, Department of Bacteriology and Department of Food Science, University of Wisconsin-Madison, 1550 Linden Dr., Microbial Sciences Building, Madison, WI 53706, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A thermophilic bacterium capable of low-molecular-weight polyethylene (LMWPE) degradation was isolated from a compost sample, and was identified as Chelatococcus sp. E1, through sequencing of the 16S rRNA gene. LMWPE was prepared by thermal degradation of commercial PE in a strict nitrogen atmosphere. LMWPE with a weight-average-molecular-weight (Mw) in the range of 1,700–23,700 was noticeably mineralized into CO 2 by the bacterium. The biodegradability of LMWPE decreased as the Mw increased. The low molecular weight fraction of LMWPE decreased significantly as a result of the degradation process, and thereby both the number-average-molecular-weight and Mw increased after biodegradation. The polydispersity of LMWPE was either narrowed or widened, depending on the initial Mw of LMWPE, due to the preferential elimination of the low molecular weight fraction, in comparison to the high molecular weight portion. LMWPE free from an extremely low molecular weight fraction was also mineralized by the strain at a remarkable rate, and FTIR peaks assignable to C–O stretching appeared as a result of microbial action. The FTIR peaks corresponding to alkenes also became more intense, indicating that dehydrogenations occurred concomitantly with microbial induced oxidation. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-012-9560-y Authors Hyun Jeong Jeon, Department of Life Science, Sangmyung University, Seoul, 110-743 Republic of Korea Mal Nam Kim, Department of Life Science, Sangmyung University, Seoul, 110-743 Republic of Korea Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The contamination of groundwater with mercury (Hg) is an increasing problem worldwide. Yet, little is known about the interactions of Hg with microorganisms and their processes in subsurface environments. We tested the impact of Hg on denitrification in nitrate reducing enrichment cultures derived from subsurface sediments from the Oak Ridge Integrated Field Research Challenge site, where nitrate is a major contaminant and where bioremediation efforts are in progress. We observed an inverse relationship between Hg concentrations and onset and rates of denitrification in nitrate enrichment cultures containing between 53 and 1.1 μM of inorganic Hg; higher Hg concentrations increasingly extended the time to onset of denitrification and inhibited denitrification rates. Microbial community complexity, as indicated by terminal restriction fragment length polymorphism (tRFLP) analysis of the 16S rRNA genes, declined with increasing Hg concentrations; at the 312 nM Hg treatment, a single tRFLP peak was detected representing a culture of Bradyrhizobium sp. that possessed the merA gene indicating a potential for Hg reduction. A culture identified as Bradyrhizobium sp. strain FRC01 with an identical 16S rRNA sequence to that of the enriched peak in the tRFLP patterns, reduced Hg(II) to Hg(0) and carried merA whose amino acid sequence has 97 % identity to merA from the Proteobacteria and Firmicutes . This study demonstrates that in subsurface sediment incubations, Hg may inhibit denitrification and that inhibition may be alleviated when Hg resistant denitrifying Bradyrhizobium spp. detoxify Hg by its reduction to the volatile elemental form. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10532-012-9555-8 Authors Yanping Wang, Department of Biochemistry and Microbiology, Rutgers University, 223C Lipman Hall, 76 Lipman Dr., New Brunswick, NJ 08901, USA Heather A. Wiatrowski, Department of Biology, Clark University, Worcester, MA 01610-1477, USA Ria John, Department of Biochemistry and Microbiology, Rutgers University, 223C Lipman Hall, 76 Lipman Dr., New Brunswick, NJ 08901, USA Chu-Ching Lin, Graduate Institute of Environmental Engineering, National Central University, Taoyuan, 32001 Taiwan Lily Y. Young, Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA Lee J. Kerkhof, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA Nathan Yee, Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA Tamar Barkay, Department of Biochemistry and Microbiology, Rutgers University, 223C Lipman Hall, 76 Lipman Dr., New Brunswick, NJ 08901, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A gram-positive bacterium Citricoccus nitrophenolicus (strain PNP1 T , DSM 23311 T , CCUG 59571 T ) isolated from a waste water treatment plant was capable of effectively degrading p -nitrophenol (pNP) as a source of carbon, nitrogen and energy for growth. Degradation of pNP required oxygen and resulted in the stoichiometric release of nitrite. Strain PNP1 T also degraded 4-chlorophenol, phenol and salicylate. pNP was degraded at pH values between 6.8 and 10.0 and at temperatures between 15–32 °C. pNP at concentrations up to 150 mg L −1 were degraded during growth in media at pH ≤ 10, whereas 200 mg L −1 was completely inhibitory to growth. When incubated in an NH 4 Cl-free medium (pH 10) containing both pNP and acetate, pNP is degraded with concomitant release of nitrite which was subsequently assimilated during acetate degradation. Intact cells of strain PNP1 T suspended in NaHCO 3 /Na 2 CO 3 buffer were able to continuously degrade 200 mg L −1 pNP over a 40 day period at pH 10. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9559-4 Authors Marie Bank Nielsen, Department of Bioscience, Microbiology, Aarhus University, Ny Munkegade 114-116, Building 1540, 8000 Aarhus C, Denmark Kjeld Ingvorsen, Department of Bioscience, Microbiology, Aarhus University, Ny Munkegade 114-116, Building 1540, 8000 Aarhus C, Denmark Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A lead resistant bacterial strain isolated from effluent of lead battery manufacturing company of Goa, India has been identified as Enterobacter cloacae strain P2B based on morphological, biochemical characters, FAME profile and 16S rDNA sequence data. This bacterial strain could resist lead nitrate up to 1.6 mM. Significant increase in exopolysaccharide (EPS) production was observed as the production increased from 28 to 108 mg/L dry weight when exposed to 1.6 mM lead nitrate in Tris buffered minimal medium. Fourier-transformed infrared spectroscopy of this EPS revealed presence of several functional groups involved in metal binding viz. carboxyl, hydroxyl and amide groups along with glucuronic acid. Gas chromatography coupled with mass spectrometry analysis of alditol-acetate derivatives of acid hydrolysed EPS produced in presence of 1.6 mM lead nitrate demonstrated presence of several neutral sugars such as rhamnose, arabinose, xylose, mannose, galactose and glucose, which contribute to lead binding hydroxyl groups. Scanning electron microscope coupled with energy dispersive X-ray spectrometric analysis of this lead resistant strain exposed to 1.6 mM lead nitrate interestingly revealed mucous EPS surrounding bacterial cells which sequestered 17 % lead (as weight %) extracellularly and protected the bacterial cells from toxic effects of lead. This lead resistant strain also showed multidrug resistance. Thus these results significantly contribute to better understanding of structure, function and environmental application of lead-enhanced EPSs produced by bacteria. This lead-enhanced biopolymer can play a very important role in bioremediation of several heavy metals including lead. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-012-9552-y Authors Milind Mohan Naik, Laboratory of Bacterial Genetics and Environmental Biotechnology, Department of Microbiology, Goa University, Taleigao Plateau, Panaji, 403 206 Goa, India Anju Pandey, Laboratory of Bacterial Genetics and Environmental Biotechnology, Department of Microbiology, Goa University, Taleigao Plateau, Panaji, 403 206 Goa, India Santosh Kumar Dubey, Laboratory of Bacterial Genetics and Environmental Biotechnology, Department of Microbiology, Goa University, Taleigao Plateau, Panaji, 403 206 Goa, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this study, the mph gene encoding methyl parathion hydrolase from Pseudomonas sp. WBC-3 was expressed in Yarrowia lipolytica and the expressed methyl parathion hydrolase was displayed on cell surface of Y. lipolytica. The activity of methyl parathion hydrolase displayed on the yeast cells of the transformant Z51 was 59.5 U mg −1 of cell dry cells (450.6 U per mL of the culture) in the presence of 5.0 mM of Co 2+ . The displayed methyl parathion hydrolase had the optimal pH of 9.5 and the optimal temperature of 40 °C, respectively and was stable in the pH range of 4.5–11 and up to 40 °C. The displayed methyl parathion hydrolase was also stimulated by Co 2+ , Cu 2+ , Ni 2+ and Mn 2+ , and was not affected by Fe 2+ , Fe 3+ , Na + , K + , Ca 2+ and Zn 2+ , but was inhibited by other cations tested. Under the optimal conditions (OD 600nm  = 2.6, the substrate concentration = 100 mg L −1 and 40 °C), 90.8 % of methyl parathion was hydrolyzed within 30 min. Under the similar conditions, 98.7, 97.0, 96.5 and 94.4 % of methyl parathion in tap water (pH 9.5), tap water (pH 6.8), seawater (pH 9.5) and natural seawater (pH 8.2) were hydrolyzed, respectively, suggesting that the methyl parathion hydrolase displayed on the yeast cells can effectively remove methyl parathion in water. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10532-012-9551-z Authors Xing-Xing Wang, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Zhe Chi, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Shao-Guo Ru, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Zhen-Ming Chi, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Rhodococcus sp. and Pseudomonas sp. bioremediation experiments were carried out using free and immobilized cells on natural carrier material (corncob powder) in order to evaluate the feasibility of its use in the bioremediation of hydrocarbon-contaminated soils. Terminal restriction fragment length polymorphism analysis was performed on the 16S rRNA gene as molecular fingerprinting method in order to assess the persistence of inoculated strains in the soil over time. Immobilized Pseudomonas cells degraded hydrocarbons more efficiently in the short term compared to the free ones. Immobilization seemed also to increase cell growth and stability in the soil. Free and immobilized Rhodococcus cells showed comparable degradation percentages, probably due to the peculiarity of Rhodococcus cells to aggregate into irregular clusters in the presence of hydrocarbons as sole carbon source. It is likely that the cells were not properly adsorbed on the porous matrix as a result of the small size of its pores. When Rhodococcus and Pseudomonas cells were co-immobilized on the matrix, a competition established between the two strains, that probably ended in the exclusion of Pseudomonas cells from the pores. The organic matrix might act as protective agent, but it also possibly limited cell density. Nevertheless, when the cells were properly adsorbed on the porous matrix, the immobilization became a suitable bioremediation strategy. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-012-9553-x Authors Valentina Rivelli, Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy Andrea Franzetti, Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy Isabella Gandolfi, Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy Sergio Cordoni, GioEco srl, Via Leonardo Da Vinci 13, 20090 Segrate, MI, Italy Giuseppina Bestetti, Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Given that the intensive application of sulfonamides in aquaculture, animal husbandry and malaria treatment has lead to an increase in sulfonamide discharge into the environment, there is an increasing need to find a way to remediate sulfonamide-contaminated sites. The bacterial strain DX7 was isolated from a marine environment and is capable of degrading sulfadoxine. DX7 was identified as a Pseudomonas sp. based on 16S rRNA gene sequencing. Approximately 30% of sulfadoxine was degraded after Pseudomonas sp. DX7 was inoculated into mineral salt plus tryptone media containing 10 mg l −1 sulfadoxine for 2 days. The degradation efficiency under different environmental conditions was characterized using HPLC. The optimal temperature and pH for sulfadoxine biodegradation were around 30°C and 6.0, respectively. The optimal concentrations of sulfadoxine and tryptone for sulfadoxine biodegradation were determined to be approximately 30 mg l −1 and between 2.0 and 8.0 g l −1 , respectively. Cytotoxicity analysis indicated that the metabolites of sulfadoxine generated by Pseudomonas sp. DX7 showed significantly reduced cytotoxicity to Hela cells. These results suggest that Pseudomonas sp. DX7 is a new bacterial resource for degrading sulfadoxine and indicate the potential of the isolated strain in the bioremediation of sulfadoxine-contaminated environments. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-011-9522-9 Authors Weiwei Zhang, Key Laboratory of Coastal Environmental Processes, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003 China Dongxue Xu, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China Zongliang Niu, Key Laboratory of Coastal Environmental Processes, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003 China Kun Yin, Key Laboratory of Coastal Environmental Processes, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003 China Ping Liu, Key Laboratory of Coastal Environmental Processes, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003 China Lingxin Chen, Key Laboratory of Coastal Environmental Processes, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Microbial enzymes that can hydrolyze organophosphorus compounds have been isolated, identified and characterized from different microbial species in order to use them in biodegradation of organophosphorus compounds. We isolated a bacterial strain Cons002 from an agricultural soil bacterial consortium, which can hydrolyze methyl-parathion (MP) and other organophosphate pesticides. HPLC analysis showed that strain Cons002 is capable of degrading pesticides MP, parathion and phorate. Pulsed-field gel electrophoresis and 16S rRNA amplification were performed for strain characterization and identification, respectively, showing that the strain Cons002 is related to the genus Enterobacter sp. which has a single chromosome of 4.6 Mb and has no plasmids. Genomic library was constructed from DNA of Enterobacter sp. Cons002. A gene called opdE ( O rganophosphate D egradation from E nterobacter ) consists of 753 bp and encodes a protein of 25 kDa, which was isolated using activity methods. This gene opdE had no similarity to any genes reported to degrade organophosphates. When kanamycin-resistance cassette was placed in the gene opdE , hydrolase activity was suppressed and Enterobacter sp. Cons002 had no growth with MP as a nutrients source. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10532-011-9517-6 Authors Concepción Chino-Flores, Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico Edgar Dantán-González, Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico Alejandra Vázquez-Ramos, Instituto de Biotecnología, UNAM, Cuernavaca, Mexico Raunel Tinoco-Valencia, Instituto de Biotecnología, UNAM, Cuernavaca, Mexico Rafael Díaz-Méndez, Centro de Ciencias Genómicas, UNAM, Cuernavaca, Mexico Enrique Sánchez-Salinas, Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico Ma. Luisa Castrejón-Godínez, Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico Fernando Ramos-Quintana, Instituto Tecnológico de Estudios Superiores de Monterrey, Cuernavaca, Mexico Ma. Laura Ortiz-Hernández, Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In the present study, the bioremoval of Cr(VI) and the removal of total organic carbon (TOC) were achieved with a system composed by an anaerobic filter and a submerged biofilter with intermittent aeration using a mixed culture of microorganisms originating from contaminated sludge. In the aforementioned biofilters, the concentrations of chromium, carbon, and nitrogen were optimized according to response surface methodology. The initial concentration of Cr(VI) was 137.35 mg l −1 , and a bioremoval of 85.23% was attained. The optimal conditions for the removal of TOC were 4 to 8 g l −1 of sodium acetate, 〉0.8 g l −1 of ammonium chloride and 60 to 100 mg l −1 of Cr(VI). The results revealed that ammonium chloride had the strongest effect on the TOC removal, and 120 mg l −1 of Cr(VI) could be removed after 156 h of operation. Moreover, 100% of the Cr(VI) and the total chromium content of the aerobic reactor output were removed, and TOC removals of 80 and 87% were attained after operating the anaerobic and aerobic reactors for 130 and 142 h, respectively. The concentrations of cells in both reactors remained nearly constant over time. The residence time distribution was obtained to evaluate the flow through the bioreactors. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10532-011-9523-8 Authors Daniela M. A. Leles, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Diego A. Lemos, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Ubirajara C. Filho, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Lucienne L. Romanielo, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Miriam M. de Resende, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Vicelma L. Cardoso, Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Bloco 1K, Uberlândia, MG 38408-100, Brazil Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The accelerating effect of non-dissolved redox mediator (1,5-dichloroanthraquinone) on the biological denitrification was investigated in this paper using 1,5-dichloroanthraquinone immobilized by calcium alginate (CA) and a heterotrophic denitrification bacterium of Paracoccus versutus (GU111570). The results suggested that the denitrification rate was enhanced 2.1 fold by 25 mmol l −1 1,5-dichloroanthraquinone of this study, and a positive correlation was found for the denitrification rate and 1,5-dichloroanthraquinone concentrations from 0 to 25 mmol l −1 . According to the change characteristic of NO 3 − and NO 2 − during the denitrification process, the tentative accelerating mechanism of the denitrification by redox mediators was put forward, and redox mediator might play the role of reduced cofactors like NADH, N(A)DH and SDH, or the similar ubiquinol/ubiquinone (Q/QH 2 ) role during the denitrification process. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10532-011-9518-5 Authors Huijuan Liu, State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Jianbo Guo, State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Jiuhui Qu, State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Jing Lian, School of Environmental Science and Engineering, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang City, 050018 People’s Republic of China William Jefferson, State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Jingliang Yang, School of Environmental Science and Engineering, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang City, 050018 People’s Republic of China Haibo Li, School of Environmental Science and Engineering, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang City, 050018 People’s Republic of China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    For waste management, methane emissions from landfills and their effect on climate change are of serious concern. Current models for biogas generation that focus on the economic use of the landfill gas are usually based on first order chemical reactions (exponential decay), underestimating the long-term emissions of landfills. The presented study concentrated on the curve fitting and the quantification of the gas generation during the final degradation phase under optimal anaerobic conditions. For this purpose the long-term gas generation (240–1,830 days) of different mechanically biologically treated (MBT) waste materials was measured. In this study the late gas generation was modeled by a log–normal distribution curve to gather the maximum gas generation potential. According to the log–normal model the observed gas sum curve leads to higher values than commonly used exponential decay models. The prediction of the final phase of landfill gas generation by a fitting model provides a basis for CO 2 balances in waste management and some information to which extent landfills serve as carbon sink. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10532-011-9519-4 Authors Johannes Tintner, Department of Water, Atmosphere and Environment, Institute of Waste Management, University of Natural Resources and Life Sciences, Vienna, Austria Manfred Kühleitner, Department of Integrative Biology, Institute of Mathematics, University of Natural Resources and Life Sciences, Vienna, Austria Erwin Binner, Department of Water, Atmosphere and Environment, Institute of Waste Management, University of Natural Resources and Life Sciences, Vienna, Austria Norbert Brunner, Department of Integrative Biology, Institute of Mathematics, University of Natural Resources and Life Sciences, Vienna, Austria Ena Smidt, Department of Water, Atmosphere and Environment, Institute of Waste Management, University of Natural Resources and Life Sciences, Vienna, Austria Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Four identical lab scale sequencing batch reactors R, R1, R2, and R3, were used to assess nitrophenol biodegradation using a single sludge biomass containing Thiosphaera pantotropha. Nitrophenols [4-Nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP) and 2,4,6-trinitrophenol (2,4,6-TNP)] were biotransformed by heterotrophic nitrification and aerobic denitrification (SND). Reactor R was used as background control, whereas R1, R2, and R3 were fed with 4-NP, 2,4-DNP, and 2,4,6-TNP, respectively. The concentration of each nitrophenol was gradually increased from 2.5 to 200 mg/l along with increase in COD, during acclimation studies . The final COD maintained was 4,500 mg/l with each nitrophenolic loading of 200 mg/l. During late phase of acclimation and HRT study, a filamentous organism started appearing in 2,4-DNP and 2,4,6-TNP bioreactors. Filaments were never found in 4-NP and background control reactor. Biochemistry and physiology behind filamentous organism development, was studied to obtain permanent solution for its removal. The effect of different input parameters such as COD loading, DO levels, SVI etc. were analyzed. The morphology and development of filamentous organism were examined extensively using microscopic techniques involving ESEM, oil immersion, phase contrast, and dark field microscopy. The organism was grown and isolated on selective agar plates and was identified as member of Streptomyses species. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10532-011-9524-7 Authors P. M. Kulkarni, Research Scholar, Center for Environmental Science and Engineering, Indian Institute of Technology, Bombay, Mumbai, Maharashtra, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Chrome mining activity has contributed intensively towards pollution of hexavalent chromium around Sukinda Valley, Orissa, India. In an attempt to study the specific contribution of exopolysaccharides (EPS) extracted from indigenous isolates towards Cr(VI) reduction, three chromium (VI) tolerant strains were isolated from the effluent mining sludge. Based on the tolerance towards Cr(VI) and EPS production capacity, one of them was selected for further work. The taxonomic identity of the selected strain was confirmed to be Enterobacter cloacae (showing 98% similarity in BLAST search to E . cloacae ) through 16S rRNA analysis. The EPS production was observed to increase with increasing Cr(VI) concentration in the growth medium, highest being 0.078 at 100 mg/l Cr(VI). The extracted EPS from Enterobacter cloacae SUKCr1D was able to reduce 31.7% of Cr(VI) at 10 mg/l concentration, which was relevant to the prevailing natural concentrations at Sukinda mine effluent sludge. The FT-IR spectral studies confirmed the surface chemical interactions of hexavalent chromium with EPS. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-011-9527-4 Authors R. Harish, Centre for Nanobiotechnology, School of Biosciences and Technology, VIT University, Vellore, 632014 India Jastin Samuel, Centre for Nanobiotechnology, School of Biosciences and Technology, VIT University, Vellore, 632014 India R. Mishra, Centre for Nanobiotechnology, School of Biosciences and Technology, VIT University, Vellore, 632014 India N. Chandrasekaran, Centre for Nanobiotechnology, School of Biosciences and Technology, VIT University, Vellore, 632014 India A. Mukherjee, Centre for Nanobiotechnology, School of Biosciences and Technology, VIT University, Vellore, 632014 India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The effectiveness of a passive flow sulfate-reducing bioreactor processing acid mine drainage (AMD) generated from an abandoned coal mine in Southern Illinois was evaluated using geochemical and microbial community analysis 10 months post bioreactor construction. The results indicated that the treatment system was successful in both raising the pH of the AMD from 3.09 to 6.56 and in lowering the total iron level by 95.9%. While sulfate levels did decrease by 67.4%, the level post treatment (1153 mg/l) remained above recommended drinking water levels. Stimulation of biological sulfate reduction was indicated by a +2.60‰ increase in δ 34 S content of the remaining sulfate in the water post-treatment. Bacterial community analysis targeting 16S rRNA and dsrAB genes indicated that the pre-treated samples were dominated by bacteria related to iron-oxidizing Betaproteobacteria , while the post-treated water directly from the reactor outflow was dominated by sequences related to sulfur-oxidizing Epsilonproteobacteria and complex carbon degrading Bacteroidetes and Firmicutes phylums. Analysis of the post-treated water, prior to environmental release, revealed that the community shifted back to predominantly iron-oxidizing Betaproteobacteria . DsrA analysis implied limited diversity in the sulfate-reducing population present in both the bioreactor outflow and oxidation pond samples. These results support the use of passive flow bioreactors to lower the acidity, metal, and sulfate levels present in the AMD at the Tab-Simco mine, but suggest modifications of the system are necessary to both stimulate sulfate-reducing bacteria and inhibit sulfur-oxidizing bacteria. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10532-011-9520-y Authors Andrew S. Burns, Department of Microbiology, Southern Illinois University, 1125 Lincoln Drive, Mail Code 6508, Carbondale, IL 62901, USA Charles W. Pugh, Department of Microbiology, Southern Illinois University, 1125 Lincoln Drive, Mail Code 6508, Carbondale, IL 62901, USA Yosief T. Segid, Department of Geology, Southern Illinois University, Carbondale, IL 62901, USA Paul T. Behum, Environmental Resources and Policy Program, Southern Illinois University, Carbondale, IL 62901, USA Liliana Lefticariu, Department of Geology, Southern Illinois University, Carbondale, IL 62901, USA Kelly S. Bender, Department of Microbiology, Southern Illinois University, 1125 Lincoln Drive, Mail Code 6508, Carbondale, IL 62901, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    We investigated the cellular responses of the white-rot basidiomycete Phanerochaete chrysosporium against vanillin. Based upon a proteomic survey, it was demonstrated that two flavin-containing monooxygenases (PcFMO1 and PcFMO2) are translationally up-regulated in response to exogenous addition of vanillin. To elucidate their catalytic functions, we cloned cDNAs and heterologously expressed them in Escherichia coli . The recombinant PcFMO1 showed catalytic activities against monocyclic phenols such as phenol, hydroquinone, and 4-chlorophenol. In addition, the product from hydroquinone was identified as 1,2,4-trihydroxybenzene, an important intermediate in a metabolic pathway of aromatic compounds in which the aromatic ring of 1,2,4-trihydroxybenzene can be further cleaved by fungal dioxygenases for mineralization. Thus, the ortho-cleavage pathway of phenolic compounds would presumably be associated with PcFMO1. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10532-011-9521-x Authors Tomofumi Nakamura, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan Hirofumi Ichinose, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan Hiroyuki Wariishi, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Four fungal strains— Trichoderma viride , Aspergillus niger , Trichoderma koningii , and Trichoderma reesei —were selected for cellulase production using furfural residues and microcrystalline cellulose (MCC) as the substrates. The filter paper activity (FPA) of the supernatant from each fungus was measured, and the performance of the enzymes from different fungal strains was compared. Moreover, the individual activities of the three components of the cellulase system, i.e., β-glucosidase, endoglucanase, and exoglucanase were evaluated. T. koningii showed the highest activity (27.81 FPU/ml) on furfural residues, while T. viride showed an activity of 21.61 FPU/ml on MCC. The FPA of the crude enzyme supernatant from T. koningii was 30% higher on furfural residues than on MCC. T. koningii and T. viride exhibited high stability and productivity and were chosen for cellulases production. The crystallinity index (CrI) of the furfural residues varied after digested by the fungi. The results indicated differences in the functioning of the cellulase system from each fungus. In the case of T. koningii , T. reesei and T. viride , furfural residues supported a better environment for cellulase production than MCC. Moreover, the CrI of the furfural residues decreased, indicating that this material was largely digested by the fungi. Thus, our results suggest that it may be possible to use the cellulases produced from these fungi for the simultaneous saccharification and fermentation of lignocellulosic materials in ethanol production. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10532-011-9525-6 Authors Hui-Qin Liu, Department of Chemistry and Chemical Engineering, Beijing Forestry University, Beijing, 100083 China Yue Feng, Department of Chemistry and Chemical Engineering, Beijing Forestry University, Beijing, 100083 China Dan-Qing Zhao, Department of Chemistry and Chemical Engineering, Beijing Forestry University, Beijing, 100083 China Jian-Xin Jiang, Department of Chemistry and Chemical Engineering, Beijing Forestry University, Beijing, 100083 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Nitrocellulose is one of the most commonly used compounds in ammunition and paint industries and its recalcitrance to degradation has a negative impact on human health and the environment. In this study the capability of Desulfovibrio desulfuricans ATCC 13541 to degrade nitrocellulose as binder in paint was assayed for the first time. Nitrocellulose-based paint degradation was followed by monitoring the variation in nitrate, nitrite and ammonium content in the culture medium using Ultraviolet–Visible spectroscopy. At the same time cell counts and ATP assay were performed to estimate bacterial density and activity in all samples. Infrared spectroscopy and colorimetric measurements of paint samples were performed to assess chemical and colour changes due to the microbial action. Microscope observations of nitrocellulose-based paint samples demonstrated the capability of the bacterium to adhere to the paint surface and change the paint adhesive characteristics. Finally, preliminary studies of nitrocellulose degradation pathway were conducted by assaying nitrate- and nitrite reductases activity in D.   desulfuricans grown in presence or in absence of paint. We found that D.   desulfuricans ATCC 13541 is able to transform nitrocellulose as paint binder and we hypothesised ammonification as degradation pathway. The results suggest that D.   desulfuricans ATCC 13541 is a good candidate as a nitrocellulose-degrading bacterium. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10532-012-9546-9 Authors L. Giacomucci, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy F. Toja, Dipartimento di Chimica, Materiali e Ingegneria Chimica ‘Giulio Natta’, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy P. Sanmartín, Departamento de Edafología y Química Agrícola, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain L. Toniolo, Dipartimento di Chimica, Materiali e Ingegneria Chimica ‘Giulio Natta’, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy B. Prieto, Departamento de Edafología y Química Agrícola, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain F. Villa, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy F. Cappitelli, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Laccase from Myceliophthora thermophila was covalently immobilised on Eupergit C and Eupergit C 250L yielding specific activities of up to 17 and 80 U/g, respectively. Due to its superior activity, Eupergit C 250L was chosen for further research. The somewhat lower catalytic efficiency (based on the ratio between the turnover number and the Michaelis constant, k cat /K M ) of the immobilised enzyme in comparison with that of the free enzyme was balanced by its increased stability and broader operational window related to temperature and pH. The feasibility of the immobilised laccase was tested by using a packed bed reactor (PBR) operating in consecutive cycles for the removal of Acid Green 27 dye as model substrate. High degrees of elimination were achieved (88, 79, 69 and 57% in 4 consecutive cycles), while the levels of adsorption on the support varied from 18 to 6%, proving that dye removal took place mainly due to the action of the enzyme. Finally, a continuous PBR with the solid biocatalyst was applied for the treatment of a solution containing the following endocrine disrupting chemicals: estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). At steady-state operation, E1 was degraded by 65% and E2 and EE2 were removed up to 80% and only limited adsorption of these compounds on the support, between 12 and 22%, was detected. In addition, a 79% decrease in estrogenic activity was detected in the effluent of the enzymatic reactor while only 14% was attained by inactivated laccase. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10532-011-9516-7 Authors L. Lloret, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain F. Hollmann, Department of Biotechnology, Delft University of Technology, 2628BL Delft, The Netherlands G. Eibes, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain G. Feijoo, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain M. T. Moreira, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain J. M. Lema, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    It appears that if suspended biomass washout can be reduced effectively, granule formation will be fastened in fluidized bed. Quicker reactor start-up can be anticipated especially for those system keeping slow growth bacteria such as anammox. A hybrid reactor combined fixed-bed with nonwoven fabrics as biomass carrier and fluidized bed with slow speed mechanical stirring was therefore developed, and its nitrogen removal performances was evaluated experimentally. Only in 38 days, the total nitrogen removal rate (NRR) reached to 1.9 kg(N) m −3  day −1 and then doubled within 17 days, with total nitrogen removal efficiency kept above 70%. After 180 days reactor operating, the NRR reached a maximum value of 6.6 kg(N) m −3  day −1 and the specific anammox activity was gradually constant in 0.32 kg(N) kg(VSS) −1  day −1 . Biomass attached on nonwoven fabrics could additionally improve reactor nitrogen removal by 8%. The dominant size of granular sludge reached to 0.78 mm with stirring speed adjusted from 30 to 80 rpm and the hydraulic retention time (HRT) from 8 to 1.5 h during the whole operating time. Scanning electron microscope observation showed especially compact structure of granular sludge. A 70% of anammox bacteria percentage was identified by fluorescence in situ hybridization analysis. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10532-011-9515-8 Authors Yanning Gao, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116023 China Zhijun Liu, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116023 China Fengxia Liu, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116023 China Kenji Furukawa, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Petroleum hydrocarbon is an important energy resource, but it is difficult to exploit due to the presence of dominated heavy constituents such as asphaltenes. In this study, viscosity reduction of Jodhpur heavy oil (2,637 cP at 50°C) has been carried out by the biodegradation of asphalt using a bacterial strain TERIG02. TERIG02 was isolated from sea buried oil pipeline known as Mumbai Uran trunk line (MUT) located on western coast of India and identified as Garciaella petrolearia by 16S rRNA full gene sequencing. TERIG02 showed 42% viscosity reduction when asphalt along with molasses was used as a sole carbon source compared to only asphalt (37%). The viscosity reduction by asphaltene degradation has been structurally characterized by Fourier transform infrared spectroscopy (FTIR). This strain also shows an additional preference to degrade toxic asphalt and aromatics compounds first unlike the other known strains. All these characteristics makes TERIG02 a potential candidate for enhanced oil recovery and a solution to degrading toxic aromatic compounds. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9482-0 Authors Meeta Lavania, TERI, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi, 110003 India Simrita Cheema, TERI, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi, 110003 India Priyangshu Manab Sarma, TERI, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi, 110003 India Ajoy Kumar Mandal, TERI, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi, 110003 India Banwari Lal, TERI, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi, 110003 India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The effective microbial remediation of the mercury necessitates the mercury to be trapped within the cells without being recycled back to the environment. The study describes a mercury bioaccumulating strain of Enterobacter sp., which remediated mercury from the medium simultaneous to its growth. The transmission electron micrographs and electron dispersive X-ray analysis revealed the accumulation of remediated mercury as nano-size particles in the cytoplasm as well as on the cell wall. The Enterobacter sp. in the present work was able to accumulate mercury, without being engineered in its native form. The possibility of recovering the accumulated mercury from the cells is also indicated. The applicability of the alginate immobilized cells in removing mercury from synthetic and complex industrial effluent in a batch mode was amply demonstrated. The initial load of 7.3 mg l −1 mercury in the industrial effluent was completely removed in 72 h. The cells immobilized in calcium alginate were similarly effective in the complete removal of 5 mg l −1 HgCl 2 of mercury from the synthetic effluent in less than 72 h. The immobilized cells could be reused for multiple cycles. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9483-z Authors Arvind Sinha, Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, 110016 India Sunil Kumar Khare, Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, 110016 India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Strain Yw12, isolated from activated sludge, could completely degrade and utilize methyl parathion as the sole carbon, phosphorus and energy sources for growth in the basic salt media. It could also completely degrade and utilize p -nitrophenol as the sole carbon and energy sources for growth in the minimal salt media. Phenotypic features, physiological and biochemical characteristics, and phylogenetic analysis of 16S rRNA sequence showed that this strain belongs to the genus of Agrobacterium sp. Response surface methodology was used to optimize degradation conditions. Under its optimal degradation conditions, 50 mg l −1 MP was completely degraded within 2 h by strain Yw12 and the degradation product PNP was also completely degraded within 6 h. Furthermore, strain Yw12 could also degrade phoxim, methamidophos, chlorpyrifos, carbofuran, deltamethrin and atrazine when provided as the sole carbon and energy sources. Enzymatic analysis revealed that the MP degrading enzyme of strain Yw12 is an intracellular enzyme and is expressed constitutively. These results indicated that strain Yw12 might be used as a potential and effective organophosphate pesticides degrader for bioremediation of contaminated sites. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9490-0 Authors Shenghui Wang, Graduate School, Chinese Academy of Agricultural Sciences (GS of CAAS), 12 Zhongguancun Nandajie, Beijing, 100081 China Chen Zhang, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100091 China Yanchun Yan, Graduate School, Chinese Academy of Agricultural Sciences (GS of CAAS), 12 Zhongguancun Nandajie, Beijing, 100081 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Mycobacterium chubuense strain NBB4 can grow on both alkanes and alkenes as carbon sources, and was hypothesised to be an effective bioremediation agent for chlorinated aliphatic pollutants. In this study, the ability of NBB4 to biodegrade vinyl chloride (VC), cis-dichloroethene (cDCE) and 1,2-dichloroethane (DCA) was investigated under pure-culture conditions and in microcosms. Ethene-grown NBB4 cells were capable of biodegrading VC and cDCE, while ethane-grown cells could biodegrade cDCE and DCA. The stoichiometry of inorganic chloride release (1 mol/mol in each case) indicated that VC was completely dechlorinated, while cDCE and DCA were only partially dechlorinated, yielding chloroacetate in the case of DCA, and unknown metabolites in the case of cDCE. The apparent maximum specific activities (k) of whole cells against ethene, cDCE, ethane and DCA were 93 ± 4.6, 89 ± 18, 39 ± 5.5, and 4.8 ± 0.9 nmol/min/mg protein, respectively, while the substrate affinities (K S ) of whole cells with the same substrates were 2.0 ± 0.15, 46 ± 11, 11 ± 0.33 and 4.0 ± 3.2 μM, respectively. In microcosms containing contaminated aquifer sediments and groundwater, NBB4 cells removed 85-95% of the pollutants (cDCE or DCA at 2 mM) within 24 h, and the cells remained viable for 〉1 month. Due to its favourable kinetic parameters, and robust survival and biodegradation activities, strain NBB4 is a promising candidate for bioremediation of chlorinated aliphatic pollutants. Content Type Journal Article Pages 1-14 DOI 10.1007/s10532-011-9466-0 Authors Nga B. Le, School of Molecular Bioscience, University of Sydney, Building G08, Sydney, NSW 2006, Australia Nicholas V. Coleman, School of Molecular Bioscience, University of Sydney, Building G08, Sydney, NSW 2006, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A fungus strain F-3 was selected from fungal strains isolated from forest soil in Dalian of China. It was identified as one Aspergillus sp . stain F-3 with its morphologic, cultural characteristics and high homology to the genus of rDNA sequence . The budges or thickened node-like structures are peculiar structures of hyphae of the strain. The fungus degraded 65% of alkali lignin (2,000 mg l −1 ) after day 8 of incubation at 30°C at pH 7. The removal of colority was up to 100% at 8 days. The biodegradation of lignin by Aspergillus sp . F-3 favored initial pH 7.0. Excess acid or alkali conditions were not propitious to lignin decomposing. Addition of ammonium l -tartrate or glucose delayed or repressed biodegradation activities. During lignin degradation, manganese peroxidase (28.2 U l −1 ) and laccase (3.5 U l −1 )activities were detected after day 7 of incubation. GC-MS analysis of biodegraded products showed strain F-3 could convert alkali lignin into small molecules or other utilizable products. Strain F-3 may co-culture with white rot fungus and decompose alkali lignin effectively. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9460-6 Authors Y. S. Yang, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116024 China J. T. Zhou, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116024 China H. Lu, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116024 China Y. L. Yuan, School of Environmental and Chemical Engineering, Dalian University, Dalian, 116622 China L. H. Zhao, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116024 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    As a result of bovine spongiform encephalopathy in Canada, specific tissues at risk of harbouring prions are not allowed to enter the food chain. Composting may be a viable alternative to rendering and land filling for the disposal of specified risk material (SRM). Two types of laboratory-scale composters, actively-heated and ambient systems were constructed to assess the biodegradation of SRM over 30 days. A second heating cycle was generated by mixing the compost after 15 days. Compared to ambient composters, temperature profiles in actively-heated composters were above 50°C for 5 and 4 days longer in the first and second composting cycles, respectively. Degradation of SRM was similar between two composter types during two composting cycles, averaging 52.2% in the first cycle and 43.9% in second cycle. Denaturing gradient gel electrophoresis (DGGE) revealed that changes in the actinobacteria populations in the first composting cycle were of a temporal nature, whereas alterations in populations in the second composting cycle were more related to active heating of compost. Sequencing of the dominant DGGE bands showed the predominance of Corynebacterium , Promicromonospora , Pseudonocardia , and Thermobifida in the first composting cycle and Corynebacterium , Mycobacterium, Nocardia, Saccharomonospora , and Streptomyces in the second composting cycle. Active heating can alter the nature of actinobacteria populations in compost, but does not appear to have a major impact on the extent of degradation of SRM. Content Type Journal Article Pages 1-15 DOI 10.1007/s10532-011-9461-5 Authors Shanwei Xu, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G2P5, Canada G. Douglas Inglis, Agriculture and Agri-Food Canada, Lethbridge Research Centre, PO Box 3000, Lethbridge, Alberta, T1J4B1 Canada Tim A. Reuter, Agriculture and Agri-Food Canada, Lethbridge Research Centre, PO Box 3000, Lethbridge, Alberta, T1J4B1 Canada O. Grant Clark, Department of Bioresource Engineering, McGill University, Ste-Anne-de-Bellevue, Québec, H9X3V9 Canada Miodrag Belosevic, Department of Biological Science, University of Alberta, Edmonton, AB T6G2E9, Canada Jerry J. Leonard, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G2P5, Canada Tim A. McAllister, Agriculture and Agri-Food Canada, Lethbridge Research Centre, PO Box 3000, Lethbridge, Alberta, T1J4B1 Canada Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The Test Area North (TAN) site at the Idaho National Laboratory near Idaho Falls, ID, USA, sits over a trichloroethylene (TCE) contaminant plume in the Snake River Plain fractured basalt aquifer. Past observations have provided evidence that TCE at TAN is being transformed by biological natural attenuation that may be primarily due to co-metabolism in aerobic portions of the plume by methanotrophs. TCE co-metabolism by methanotrophs is the result of the broad substrate specificity of microbial methane monooxygenase which permits non-specific oxidation of TCE in addition to the primary substrate, methane. Arrays of experimental approaches have been utilized to understand the biogeochemical processes driving intrinsic TCE co-metabolism at TAN. In this study, aerobic methanotrophs were enumerated by qPCR using primers targeting conserved regions of the genes pmoA and mmoX encoding subunits of the particulate MMO (pMMO) and soluble MMO (sMMO) enzymes , respectively, as well as the gene mxa encoding the downstream enzyme methanol dehydrogenase. Identification of proteins in planktonic and biofilm samples from TAN was determined using reverse phase ultra-performance liquid chromatography (UPLC) coupled with a quadrupole-time-of-flight (QToF) mass spectrometer to separate and sequence peptides from trypsin digests of the protein extracts. Detection of MMO in unenriched water samples from TAN provides direct evidence of intrinsic methane oxidation and TCE co-metabolic potential of the indigenous microbial population. Mass spectrometry is also well suited for distinguishing which form of MMO is expressed in situ either soluble or particulate. Using this method, pMMO proteins were found to be abundant in samples collected from wells within and adjacent to the TCE plume at TAN. Content Type Journal Article Pages 1-15 DOI 10.1007/s10532-011-9462-4 Authors Andrzej J. Paszczynski, Environmental Biotechnology Institute, University of Idaho, PO Box 441052, Moscow, ID 83844-1052, USA Ravindra Paidisetti, Environmental Biotechnology Institute, University of Idaho, PO Box 441052, Moscow, ID 83844-1052, USA Andrew K. Johnson, Environmental Biotechnology Institute, University of Idaho, PO Box 441052, Moscow, ID 83844-1052, USA Ronald L. Crawford, Environmental Biotechnology Institute, University of Idaho, PO Box 441052, Moscow, ID 83844-1052, USA Frederick S. Colwell, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR USA Tonia Green, Environmental Biotechnology Institute, University of Idaho, PO Box 441052, Moscow, ID 83844-1052, USA Mark Delwiche, Idaho National Laboratory, Idaho Falls, ID USA Hope Lee, Idaho National Laboratory, Idaho Falls, ID USA Deborah Newby, Idaho National Laboratory, Idaho Falls, ID USA Eoin L. Brodie, Lawrence Berkeley National Laboratory, Berkeley, CA USA Mark Conrad, Lawrence Berkeley National Laboratory, Berkeley, CA USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified PAHs, including high-molecular-weight compounds, were removed to a greater extent in the weekly-fed bioreactor, which achieved total PAH removal of 76%. Molecular analyses, including pyrosequencing of 16S rRNA genes, revealed significant shifts in the soil bacterial communities after introduction to the bioreactors and differences in the abundance and types of bacteria in each of the bioreactors. The weekly-fed bioreactor displayed a more stable bacterial community with gradual changes over time, whereas the monthly-fed bioreactor community was less consistent and may have been more strongly influenced by the influx of untreated soil during feeding. Phylogenetic groups containing known PAH-degrading bacteria previously identified through stable-isotope probing of the untreated soil were differentially affected by bioreactor conditions. Sequences from members of the Acidovorax and Sphingomonas genera, as well as the uncultivated “Pyrene Group 2” were abundant in the bioreactors. However, the relative abundances of sequences from the Pseudomonas , Sphingobium , and Pseudoxanthomonas genera, as well as from a group of unclassified anthracene degraders, were much lower in the bioreactors compared to the untreated soil. Content Type Journal Article Pages 1-13 DOI 10.1007/s10532-011-9463-3 Authors David R. Singleton, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA Stephen D. Richardson, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA Michael D. Aitken, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Burkholderia sp. C3 can transform polycyclic aromatic hydrocarbons (PAHs), a class of ubiquitous pollutants, through multiple pathways, indicating existence of multiple dioxygenases (Seo et al., in Biodegradation 18:123–131, 2006a ). Both phn and nag -like genes in C3 were cloned and identified with the DNA sequence alignment and the gene organization in the clusters. When cloned and expressed in Escherichia coli , either the alpha- and beta-subunits of dioxygenase of the phn genes or the ferredoxin-, alpha- and beta-subunits of the nag -like genes transformed naphthalene, phenanthrene and dibenzothiophene but at different rates. The E. coli transformant containing the phn genes transformed phenanthrene faster than that containing the nag -like genes, which was consistent with higher transcription of the phnAc gene than the nagAc -like gene in C3 in response to phenanthrene. 1-Hydroxy-2-naphthanoic acid (1H2NA) and 2-hydroxy-1-naphthanoic acid (2H1NA) (3,4- and 1,2-dioxygenation metabolites of phenanthrene, respectively) were detected in the culture medium of the phn genes transformed E. coli . The concentration of 1H2NA was 262-fold higher than 2H1NA in the medium of the phn genes transformed E. coli . The results suggested that the phn genes play a major role in 1,2-/3,4-dioxygenation and 3,4-dioxygenation dominates. Twenty-eight PAH degradation-associated enzymes including those encoded by the nag -like and phn genes in phenanthrene-grown C3 cells were identified via alignment of amino acid sequences of the detected polypeptides with those in protein databases. The polypeptides were determined with nano liquid chromatography–ion trap mass spectrometry after tryptic in-gel digestion of the enzymes on 1D SDS-PAGE. Content Type Journal Article Pages 1-15 DOI 10.1007/s10532-011-9468-y Authors Panlada Tittabutr, Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822, USA Il Kyu Cho, Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822, USA Qing X. Li, Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Two stage statistical design was used to optimize xylanase production from Bacillus pumilus ASH under solid-state fermentation. Initially, Plackett–Burman designing (PB) was used for the selection of crucial production parameters. Peptone, yeast extract, incubation time, moisture level and pH were found to be the crucial factors for the xylanase production. Crucial variables were further processed through central composite designing (CCD) of response surface methodology (RSM) to maximize the xylanase yield. Each significant factor was investigated at five different levels to study their influence on enzyme production. Statistical approach resulted in 2.19-fold increase in xylanase yield over conventional strategy. The determination coefficient ( R 2 ) as shown by analysis of variance (ANOVA) was 0.9992, which shows the adequate credibility of the model. Potential of cellulase-free xylanase was further investigated for biobleaching of wheat straw pulp. Xylanase aided bleaching through XCDED 1 D 2 sequence resulted in 20 and 17% reduction in chlorine and chlorine dioxide consumption as compared to control. Significant increase in pulp brightness (%ISO), whiteness and improvement in various pulp properties was also observed. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9470-4 Authors Gaurav Garg, Department of Biotechnology, Kurukshetra University, Kurukshetra, 136 119 India Ritu Mahajan, Department of Biotechnology, Kurukshetra University, Kurukshetra, 136 119 India Amanjot Kaur, Department of Biotechnology, Kurukshetra University, Kurukshetra, 136 119 India Jitender Sharma, Department of Biotechnology, Kurukshetra University, Kurukshetra, 136 119 India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    One hundred and two basidiomycete strains (93 species in 41 genera) that prefer a soil environment were examined for screening of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) biodegradation. Three strains within two litter-decomposing genera, Agrocybe and Marasmiellus , were selected for their DDT biotransformation capacity. Eight metabolites; 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD), two monohydroxy-DDTs, monohydroxy-DDD, 2,2-dichloro-1,1-bis(4-chlorophenyl)ethanol, putative 2,2-bis(4-chlorophenyl)ethanol and two unidentified compounds were detected from the culture with Marasmiellus sp. TUFC10101. A P450 inhibitor, 1-ABT, inhibited the formation of monohydroxy-DDTs and monohydroxy-DDD from DDT and DDD, respectively. These results indicated that oxidative pathway which was catalyzed by P450 monooxygenase exist beside reductive dechlorination of DDT. Monohydroxylation of the aromatic rings of DDT (and DDD) by fungal P450 is reported here for the first time. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9464-2 Authors Hiroto Suhara, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553 Japan Ai Adachi, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553 Japan Ichiro Kamei, Faculty of Agriculture, Miyazaki University, 1-1 Gakuen Kibanadai-nishi, Miyazaki, 889-2192 Japan Nitaro Maekawa, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Combining chemical and biological treatments is a potentially economic approach to remove high concentration of recalcitrant compounds from wastewaters. In the present study, the biodegradation of 1,4-benzoquinone, an intermediate compound formed during phenol oxidation by chlorine dioxide, was investigated using Pseudomonas putida (ATCC 17484) in batch and continuous bioreactors. Batch experiments were conducted to determine the effects of 1,4-benzoquinone concentration and temperature on the microbial activity and biodegradation kinetics. Using the generated data, the maximum specific growth rate and biodegradation rate were determined as 0.94 h −1 and 6.71 mg of 1,4-benzoquinone l −1  h −1 . Biodegradation in a continuous bioreactor indicated a linear relationship between substrate loading and biodegradation rates prior to wash out of the cells, with a maximum biodegradation rate of 246 mg l −1  h −1 observed at a loading rate of 275 mg l −1  h −1 (residence time: 1.82 h). Biokinetic parameters were also determined using the steady state substrate and biomass concentrations at various dilution rates and compared to those obtained in batch cultures. Content Type Journal Article Pages 1-7 DOI 10.1007/s10532-011-9465-1 Authors Pardeep Kumar, Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada Mehdi Nemati, Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada Gordon A. Hill, Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In our study, early period degradation (10 days) of Scots pine ( Pinus sylvestris L.) sapwood by the brown-rot fungus Coniophora puteana (Schum.: Fr.) Karst. (BAM Ebw.15) was followed at the wood chemical composition and ultrastructurelevel, and highlighted the generation of reactive oxygen species (ROS). An advanced decay period of 50 days was chosen for comparison of the degradation dynamics. Scanning UV microspectrophotometry (UMSP) analyses of lignin distribution in wood cells revealed that the linkages of lignin and polysaccharides were already disrupted in the early period of fungal attack. An increase in the lignin absorption A 280 value from 0.24 (control) to 0.44 in decayed wood was attributed to its oxidative modification which has been proposed to be generated by Fenton reaction derived ROS. The wood weight loss in the initial degradation period was 2%, whilst cellulose and lignin content decreased by 6.7% and 1%, respectively. Lignin methoxyl (–OCH 3 ) content decreased from 15.1% (control) to 14.2% in decayed wood. Diffuse reflectance Fourier-transform infrared (DRIFT) spectroscopy corroborated the moderate loss in the hemicellulose and lignin degradation accompanying degradation. Electron paramagnetic resonance spectra and spin trapping confirmed the generation of ROS, such as hydroxyl radicals (HO ∙ ), in the early wood degradation period. Our results showed that irreversible changes in wood structure started immediately after wood colonisation by fungal hyphae and the results generated here will assist in the understanding of the biochemical mechanisms of wood biodegradation by brown-rot fungi with the ultimate aim of developing novel wood protection methods. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-010-9449-6 Authors Ilze Irbe, Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, Riga, LV-1006 Latvia Ingeborga Andersone, Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, Riga, LV-1006 Latvia Bruno Andersons, Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, Riga, LV-1006 Latvia Guna Noldt, Division of Wood Biology, Department of Wood Science, Hamburg University, Leuschnerstrasse 91, 21031 Hamburg, Germany Tatiana Dizhbite, Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, Riga, LV-1006 Latvia Nina Kurnosova, Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, Riga, LV-1006 Latvia Mari Nuopponen, Scottish Crop Research Institute, Plant Products and Food Quality Programme, Dundee, DD2 5DA Scotland, UK Derek Stewart, Scottish Crop Research Institute, Plant Products and Food Quality Programme, Dundee, DD2 5DA Scotland, UK Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy’s Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity. Content Type Journal Article Pages 1-13 DOI 10.1007/s10532-011-9457-1 Authors Robin Gerlach, Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA Erin K. Field, Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA Sridhar Viamajala, Department of Chemical and Environmental Engineering, The University of Toledo, Toledo, OH 43606, USA Brent M. Peyton, Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA William A. Apel, Biological Systems Department, Idaho National Laboratory, Idaho Falls, ID 83415, USA Al B. Cunningham, Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Biodegradation of the gasoline oxygenates methyl tertiary -butyl ether (MTBE) and ethyl tertiary -butyl ether (ETBE) can cause tertiary butyl alcohol (TBA) to accumulate in gasoline-impacted environments. One remediation option for TBA-contaminated groundwater involves oxygenated granulated activated carbon (GAC) reactors that have been self-inoculated by indigenous TBA-degrading microorganisms in ground water extracted from contaminated aquifers. Identification of these organisms is important for understanding the range of TBA-metabolizing organisms in nature and for determining whether self-inoculation of similar reactors is likely to occur at other sites. In this study 13 C-DNA-stable isotope probing (SIP) was used to identify TBA-utilizing organisms in samples of self-inoculated BioGAC reactors operated at sites in New York and California. Based on 16S rRNA nucleotide sequences, all TBA-utilizing organisms identified were members of the Burkholderiales order of the β - proteobacteria. Organisms similar to Cupriavidus and Methylibium were observed in both reactor samples while organisms similar to Polaromonas and Rhodoferax were unique to the reactor sample from New York. Organisms similar to Hydrogenophaga and Paucibacter strains were only detected in the reactor sample from California. We also analyzed our samples for the presence of several genes previously implicated in TBA oxidation by pure cultures of bacteria. Genes Mpe_B0532, B0541, B0555, and B0561 were all detected in 13 C-metagenomic DNA from both reactors and deduced amino acid sequences suggested these genes all encode highly conserved enzymes. One gene (Mpe_B0555) encodes a putative phthalate dioxygenase-like enzyme that may be particularly appropriate for determining the potential for TBA oxidation in contaminated environmental samples. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9455-3 Authors Denise Aslett, Department of Microbiology, 4545 Thomas Hall, North Carolina State University, Raleigh, NC 27695, USA Joseph Haas, Office of the New York State Attorney General, Environmental Protection Bureau, New York, NY 10271, USA Michael Hyman, Department of Microbiology, 4545 Thomas Hall, North Carolina State University, Raleigh, NC 27695, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Cultivation-independent analyses were applied to study the structural diversity of the bacterial community which developed in groundwater inoculated microcosms actively metabolizing monochlorobenzene (MCB) under anaerobic conditions. Addition of 13 C-labelled MCB demonstrated that the community produced 13 CO 2 as a metabolite at slightly increasing rates over a period of 1,051 days while no 13 C-methane evolved. Genetic profiles of partial 16S rRNA genes generated with the single-strand conformation polymorphism (SSCP) technique by PCR from directly extracted total DNA revealed that, despite the long incubation period, six replicate microcosms were characterized by almost the same microbial members. Nine distinguishable contributors to the SSCP-profiles were characterized by DNA sequencing, revealing the presence of different members from the phyla Proteobacteria , Fibrobacteres and from the candidate division OD1. DNA-stable isotope probing (SIP) was applied to distinguish the actual MCB metabolizing bacteria from the other community members. This study reveals for the first time the structural diversity of an anaerobic MCB metabolizing bacterial community. However, it also demonstrates the limitations of SIP to detect bacteria slowly metabolizing carbon sources under anaerobic conditions. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9456-2 Authors Paula M. Martínez-Lavanchy, Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318 Leipzig, Germany Anja Bettina Dohrmann, Institut für Biodiversität, Johann Heinrich von Thünen-Institut (vTI), Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei, Bundesallee 50, 38116 Braunschweig, Germany Gwenaël Imfeld, Laboratory of Hydrology and Geochemistry of Strasbourg (LHyGeS), Université de Strasbourg/ENGEES, CNRS, 1 rue Blessing, F-67084, 67070 Strasbourg, France Karin Trescher, Institut für Biodiversität, Johann Heinrich von Thünen-Institut (vTI), Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei, Bundesallee 50, 38116 Braunschweig, Germany Christoph C. Tebbe, Institut für Biodiversität, Johann Heinrich von Thünen-Institut (vTI), Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei, Bundesallee 50, 38116 Braunschweig, Germany Hans-Hermann Richnow, Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318 Leipzig, Germany Ivonne Nijenhuis, Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318 Leipzig, Germany Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this study, a single-stage autotrophic nitrogen removal reactor, packed with a novel acrylic fiber biomass carrier material (Biofix), was applied for nitrogen removal from sludge digester liquor. For rapid start-up, conventional activated sludge was added to the reactor soon after the attachment of anammox biomass on the Biofix carriers, which allowed conventional activated sludge to form a protective layer of biofilm around the anammox biomass. The Nitrogen removal efficiency reached 75% within 1 week at a nitrogen loading rate of 0.46 kg-N/m 3 /day for synthetic wastewater treatment. By the end of the synthetic wastewater treatment period, the maximum nitrogen removal rate had increased to 0.92 kg-N/m 3 /day at a nitrogen loading rate of 1.0 kg-N/m 3 /day. High nitrogen removal rate was also achieved during the actual raw digester liquor treatment with the highest nitrogen removal rate being 0.83 kg-N/m 3 /day at a nitrogen loading rate of 0.93 kg-N/m 3 /day. The thick biofilm on Biofix carriers allowed anammox bacteria to survive under high DO concentration of 5–6 mg/l resulting in stable and high nitrogen removal performance. FISH and CLSM analysis demonstrated that anammox bacteria coexisted and surrounded by ammonium oxidizing bacteria. Content Type Journal Article Pages 1-8 DOI 10.1007/s10532-011-9495-8 Authors Sen Qiao, Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, Dalian, 116024 P. R. China Takashi Nishiyama, Department of Applied Life Science, Sojo University, Ikeda 4-22-1, Kumamoto, 860-0082 Japan Tatsuo Fujii, Department of Applied Life Science, Sojo University, Ikeda 4-22-1, Kumamoto, 860-0082 Japan Zafar Bhatti, Environmental Assessment and Approvals Branch, Ontario Ministry of the Environment, 2-St. Clair Ave. W, 12A F, Toronto, ON M4V 1L5, Canada Kenji Furukawa, Graduate School of Science and Technology, Kumamoto University, Kurokami 2-39-1, Kumamoto, 860-8555 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    An integrated photocatalytic-biological reactor (IPBR) was used for accelerated degradation and mineralization of 2,4,6-trichlorophenol (TCP) through simultaneous, intimate coupling of photocatalysis and biodegradation in one reactor. Intimate coupling was realized by circulating the IPBR’s liquid contents between a TiO 2 film on mat glass illuminated by UV light and honeycomb ceramics as biofilm carriers. Three protocols—photocatalysis alone (P), biodegradation alone (B), and integrated photocatalysis and biodegradation (photobiodegradation, P&B)—were used for degradation of different initial TCP concentrations. Intimately coupled P&B also was compared with sequential P and B. TCP removal by intimately coupled P&B was faster than that by P and B alone or sequentially coupled P and B. Because photocatalysis relieved TCP inhibition to biodegradation by decreasing its concentration, TCP biodegradation could become more important over the full batch P&B experiments. When phenol, an easy biodegradable compounds, was added to TCP in order to promote TCP mineralization by means of secondary utilization, P&B was superior to P and B in terms of mineralization of TCP, giving 95% removal of chemical oxygen demand. Cl − was only partially released during P experiments (24%), and this corresponded to its poor mineralization in P experiments (32%). Thus, intimately coupled P&B in the IPBR made it possible obtain the best features of each: rapid photocatalytic transformation in parallel with mineralization of photocatalytic products. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9498-5 Authors Yongming Zhang, Department of Environmental Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, 200234 People’s Republic of China Xia Sun, Department of Environmental Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, 200234 People’s Republic of China Lujun Chen, School of Environment, Tsinghua University, Beijing, 100084 People’s Republic of China Bruce E. Rittmann, Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Tributyl phosphate (TBP) is an organophosphorous compound, used extensively (3000–5000 tonnes/annum) as a solvent for nuclear fuel processing and as a base stock in the formulation of fire-resistant aircraft hydraulic fluids and other applications. Because of its wide applications and relative stability in the natural environment TBP poses the problem of pollution and health hazards. In the present study, fifteen potent bacterial strains capable of using tributyl phosphate (TBP) as sole carbon and phosphorus source were isolated from enrichment cultures. These isolates were identified on the basis of biochemical and morphological characteristics and 16S rRNA gene sequence analysis. Phylogenetic analysis of 16S rRNA gene sequences revealed that two isolates belonged to class Bacilli and thirteen to β and γ-Proteobacteria. All these isolates were found to be members of genera Alcaligenes, Providencia, Delftia, Ralstonia, and Bacillus. These isolates were able to tolerate and degrade up to 5 mM TBP, the highest concentration reported to date. The GC–MS method was developed to monitor TBP degradation. Two strains, Providencia sp. BGW4 and Delftia sp. BGW1 showed respectively, 61.0 ± 2.8% and 57.0 ± 2.0% TBP degradation within 4 days. The degradation rate constants, calculated by first order kinetic model were between 0.0024 and 0.0099 h −1 . These bacterial strains are novel for TBP degradation and could be used as an important bioresource for efficient decontamination of TBP polluted waste streams. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9496-7 Authors Kedar C. Ahire, Department of Microbiology, University of Pune, Pune, 411 007 India Balu P. Kapadnis, Department of Microbiology, University of Pune, Pune, 411 007 India Girish J. Kulkarni, Molecular Biology Unit, National Centre for Cell Science, Pune, 411007 India Yogesh S. Shouche, Molecular Biology Unit, National Centre for Cell Science, Pune, 411007 India Rajendra L. Deopurkar, Department of Microbiology, University of Pune, Pune, 411 007 India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The anaerobic thermophilic bacterium, Clostridium thermocellum , is a potent cellulolytic microorganism that produces large extracellular multienzyme complexes called cellulosomes. To isolate C. thermocellum organisms that possess effective cellulose-degrading ability, new thermophilic cellulolytic strains were screened from more than 800 samples obtained mainly from agriculture residues in Thailand using microcrystalline cellulose as a carbon source. A new strain, C. thermocellum S14, having high cellulose-degrading ability was isolated from bagasse paper sludge. Cellulosomes prepared from S14 demonstrated faster degradation of microcrystalline cellulose, and 3.4- and 5.6-fold greater Avicelase activity than those from C. thermocellum ATCC27405 and JW20 (ATCC31449), respectively. Scanning electron microscopic analysis showed that S14 had unique cell surface features with few protuberances in contrast to the type strains. In addition, the cellulosome of S14 was resistant to inhibition by cellobiose that is a major end product of cellulose hydrolysis. Saccharification tests conducted using rice straw soaked with sodium hydroxide indicated the cellulosome of S14 released approximately 1.5-fold more total sugars compared to that of ATCC27405. This newly isolated S14 strain has the potential as an enzyme resource for effective lignocellulose degradation. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9486-9 Authors Chakrit Tachaapaikoon, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Akihiko Kosugi, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Patthra Pason, Pilot Plant Development and Training Institute (PDTI), King Mongkut’s University of Technology Thonburi (KMUTT), Bangkok, Thailand Rattiya Waeonukul, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Khanok Ratanakhanokchai, School of Bioresources and Technology, King Mongkut’s University of Technology, Thonburi (KMUTT), Bangkok, Thailand Khin Lay Kyu, School of Bioresources and Technology, King Mongkut’s University of Technology, Thonburi (KMUTT), Bangkok, Thailand Takamitsu Arai, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Yoshinori Murata, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Yutaka Mori, Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Presence of microcystin (MC), a predominant freshwater algal toxin and a suspected liver carcinogen, in Florida’s freshwaters poses serious health threat to humans and aquatic species. Being recalcitrant to conventional physical and chemical water treatment methods, biological methods of MC removal is widely researched. Water samples collected from five sites of Lake Okeechobee (LO) frequently exposed to toxic Microcystis blooms were used as inoculum for enrichment with microcystin LR (MC-LR) supplied as sole C and N source. After 20 days incubation, MC levels were analyzed using high performance liquid chromatography (HPLC). A bacterial consortium consisting of two isolates DC7 and DC8 from the Indian Prairie Canal sample showed over 74% toxin degradation at the end of day 20. Optimal temperature requirement for biodegradation was identified and phosphorus levels did not affect the MC biodegradation. Based on 16S rRNA sequence similarity the isolate DC8 was found to have a match with Microbacterium sp. and the DC7 isolate with Rhizobium gallicum (AY972457). Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9484-y Authors A. Ramani, Department of Earth and Environment, Florida International University, 11200 SW 8th Street, Miami, FL 33199-001, USA K. Rein, Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA K. G. Shetty, Department of Earth and Environment, Florida International University, 11200 SW 8th Street, Miami, FL 33199-001, USA K. Jayachandran, Department of Earth and Environment, Florida International University, 11200 SW 8th Street, Miami, FL 33199-001, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The performance of diesel oil degradation by Candida tropicalis immobilized on various conventional matrices (sodium alginate, carboxyl methyl cellulose, chitosan) and biowaste materials (wheat bran, sawdust, peanut hull powder) was investigated using the method of entrapment and physical adsorption. The yeast species immobilized in wheat bran showed enhanced efficiency in degrading diesel oil (98%) compared to free cells culture (80%) over a period of 7 days. Copious amount of exopolysaccharides were also produced in the presence of diesel oil. The biofilm forming ability of C. tropicalis on PVC strips was evaluated using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay and monitored by scanning electron microscopy and atomic force microscopy. Yeast biofilm formed on gravels showed 97% degradation of diesel oil over a period of 10 days. The potential use of the biofilms for preparing trickling filters (gravel particles), for attenuating hydrocarbons in oily liquid wastes before their disposal in the open environment is suggested and discussed. This is the first successful attempt for ‘artificially’ establishing hydrocarbon degrading yeast biofilm on solid substrates. Content Type Journal Article Pages 1-9 DOI 10.1007/s10532-011-9473-1 Authors Preethy Chandran, Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, 632 014 Tamil Nadu, India Nilanjana Das, Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, 632 014 Tamil Nadu, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Reject water treatment performance was investigated by whole cell anammox sludge entrapped polyvinyl alcohol/sodium alginate gel in the stirred tank reactor (STR). The whole experiment was conducted through Phase 1 and Phase 2 in which synthetic wastewater and modified reject water were used as feeding medium, respectively. The anammox reactor demonstrated quick start-up after 22 days as well as stable and relatively high nitrogen removal rate of more than 8.0 kg-N m −3  day −1 during the two both phases even under moderately low temperature of 25 ± 0.5°C during the last 2 months of Phase 2. The matured brownish red PVA beads had good characteristics with buoyant density of 1.10 g cm −3 , settling velocity of 141 m h −1 and diameter of 4 mm. The bacterial community was identified by 16S rDNA analysis revealing the concurrent existence of KSU-1 and new kind anammox bacterium Kumadai-I after changing influent from synthetic wastewater to reject water. It was speculated that Kumadai-I might play a role as “promotion” factor together with KSU-1 on high nitrogen removal rate. These results demonstrate the potential application of whole cell anammox entrapment by PVA/alginate gel for achieving stable and high-rate nitrogen removal from high ammonium with low C/N ratio contained wastewaters, such as reject water, digester liquor or landfill leachate. Content Type Journal Article Pages 1-13 DOI 10.1007/s10532-011-9471-3 Authors Lai Minh Quan, Graduate School of Science and Technology (GSST), Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555 Japan Do Phuong Khanh, Graduate School of Science and Technology (GSST), Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555 Japan Daisuke Hira, Graduate School of Science and Technology (GSST), Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555 Japan Takao Fujii, Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082 Japan Kenji Furukawa, Graduate School of Science and Technology (GSST), Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Groundwater contamination by the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a global problem. Israel’s coastal aquifer was contaminated with RDX. This aquifer is mostly aerobic and we therefore sought aerobic bacteria that might be involved in natural attenuation of the compound in the aquifer. RDX-degrading bacteria were captured by passively sampling the indigenous bacteria onto sterile sediments placed within sampling boreholes. Aerobic RDX biodegradation potential was detected in the sediments sampled from different locations along the plume. RDX degradation with the native sampled consortium was accompanied by 4-nitro-2,4-diazabutanal formation. Two bacterial strains of the genus Rhodococcus were isolated from the sediments and identified as aerobic RDX degraders. The xplA gene encoding the cytochrome P450 enzyme was partially (~500 bp) sequenced from both isolates. The obtained DNA sequences had 99% identity with corresponding gene fragments of previously isolated RDX-degrading Rhodococcus strains. RDX degradation by both strains was prevented by 200 μM of the cytochrome P450 inhibitor metyrapone, suggesting that cytochrome P450 indeed mediates the initial step in RDX degradation. RDX biodegradation activity by the T7 isolate was inhibited in the presence of nitrate or ammonium concentrations above 1.6 and 5.5 mM, respectively (100 mg l −1 ) while the T9N isolate’s activity was retarded only by ammonium concentrations above 5.5 mM. This study shows that bacteria from the genus Rhodococcus , potentially degrade RDX in the saturated zone as well, following the same aerobic degradation pathway defined for other Rhodococcus species. RDX-degrading activity by the Rhodococcus species isolate T9N may have important implications for the bioremediation of nitrate-rich RDX-contaminated aquifers. Content Type Journal Article Pages 1-9 DOI 10.1007/s10532-011-9458-0 Authors Anat Bernstein, Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990 Beer Sheva, Israel Eilon Adar, Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990 Beer Sheva, Israel Ali Nejidat, Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990 Beer Sheva, Israel Zeev Ronen, Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990 Beer Sheva, Israel Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Plutonium (Pu), a key contaminant at sites associated with the manufacture of nuclear weapons and with nuclear-energy wastes, can be precipitated to “immobilized” plutonium phases in systems that promote bioreduction. Ferric iron (Fe 3+ ) is often present in contaminated sites, and its bioreduction to ferrous iron (Fe 2+ ) may be involved in the reduction of Pu to forms that precipitate. Alternately, Pu can be reduced directly by the bacteria. Besides Fe, contaminated sites often contain strong complexing ligands, such as nitrilotriacetic acid (NTA). We used biogeochemical modeling to interpret the experimental fate of Pu in the absence and presence of ferric iron (Fe 3+ ) and NTA under anaerobic conditions. In all cases, Shewanella alga BrY ( S. alga ) reduced Pu(V)(PuO 2 + ) to Pu(III), and experimental evidence indicates that Pu(III) precipitated as PuPO 4(am). In the absence of Fe 3+ and NTA, reduction of PuO 2 + was directly biotic, but modeling simulations support that PuO 2 + reduction in the presence of Fe 3+ and NTA was due to an abiotic stepwise reduction of PuO 2 + to Pu 4+ , followed by reduction of Pu 4+ to Pu 3+ , both through biogenically produced Fe 2+ . This means that PuO 2 + reduction was slowed by first having Fe 3+ reduced to Fe 2+ . Modeling results also show that the degree of PuPO 4(am) precipitation depends on the NTA concentration. While precipitation out-competes complexation when NTA is present at the same or lower concentration than Pu, excess NTA can prevent precipitation of PuPO 4(am) . Content Type Journal Article Pages 1-9 DOI 10.1007/s10532-010-9451-z Authors Randhir P. Deo, Chemistry Department, Division of Natural Sciences, College of Natural and Applied Sciences, University of Guam, Mangilao, Guam, 96923 USA Bruce E. Rittmann, Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701, USA Donald T. Reed, Los Alamos National Laboratory, Environmental and Earth Sciences Division, Carlsbad Environmental Monitoring and Research Center, Carlsbad, NM 88220, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A leuco derivatives of triphenylmethane dyes degrading bacterium, strain CM9, was isolated from an aquafarm field. Based on morphology, physiologic tests, 16S rDNA sequence, and phylogenetic characteristics, it was identified as Sphingomonas sp. This strain was capable of degrading leucomalachite green (LMG), leucocrystal violet and leucobasic fuchsin completely. The relationship between bacterium growth and LMG degradation suggested that strain CM9 could use LMG as the sole source of carbon. The most LMG degradation activity of CM9 crude extract was observed at pH 7.0 and at 30°C. Many metal ions had little inhibition effect on the degradation activity of the crude extract. CM9 also showed strong decolorization of triphenylmethane dyes to their leuco derivatives. GC/MS analysis detected two novel metabolic products, methylbenzene and 4-aminophenol, during the LMG degradation by CM9. Content Type Journal Article DOI 10.1007/s10532-010-9447-8 Authors Jun Wu, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Liguan Li, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Hongwei Du, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Lijuan Jiang, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Qiong Zhang, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Zhongbo Wei, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Xiaolin Wang, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Lin Xiao, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Liuyan Yang, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Estuaries are often considered sinks for contaminants and the cleanup of salt marshes, sensitive ecosystems with a major ecological role, should be carried out by means of least intrusive approaches, such as bioremediation. This study was designed to evaluate the influence of plant–microorganisms associations on petroleum hydrocarbons fate in salt marshes of a temperate estuary (Lima River, NW Portugal). Sediments un-colonized and colonized (rhizosediments) by different plants (Juncus maritimus, Phragmites australis, Triglochin striata and Spartina patens) were sampled in four sites of the lower and middle estuary for hydrocarbon degrading microorganisms (HD), total cell counts (TCC) and total petroleum hydrocarbons (TPHs) assessment. In general, TPHs, HD and TCC were significantly higher ( P  〈 0.05) in rhizosediments than in un-colonized sediments. Also recorded were differences on the abundance of hydrocarbon degraders among the rhizosediment of the different plants collected at the same site ( J. maritimus  〈  P. australis  〈  T. striata ), with statistically significant differences ( P  〈 0.05) between J. maritimus and T. striata . Moreover, strong positive correlations—0.81 and 0.84 ( P  〈 0.05), between biotic (HD) and abiotic (organic matter content) parameters and TPHs concentrations were also found. Our data clearly suggest that salt marsh plants can influence the microbial community, by fostering the development of hydrocarbon-degrading microbial populations in its rhizosphere, an effect observed for all plants. This effect, combined with the plant capability to retain hydrocarbons around the roots, points out that salt marsh plant–microorganisms associations may actively contribute to hydrocarbon removal and degradation in estuarine environments. Content Type Journal Article DOI 10.1007/s10532-010-9446-9 Authors Hugo Ribeiro, Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS-UP), Universidade do Porto, Largo Professor Abel Salazar, no. 2, 4099-003 Porto, Portugal Ana P. Mucha, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIMAR/CIIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal C. Marisa R. Almeida, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIMAR/CIIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal Adriano A. Bordalo, Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS-UP), Universidade do Porto, Largo Professor Abel Salazar, no. 2, 4099-003 Porto, Portugal Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Two chitosanases (CHSA1 and CHSA2) were purified from the culture supernatant of Acinetobacter calcoaceticus TKU024 with squid pen as the sole carbon/nitrogen source. The molecular masses of CHSA1 and CHSA2 determined by SDS-PAGE were approximately 27 and 66 kDa, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of CHSA1 and CHSA2 were (pH 6, 50°C, pH 4–10, 〈90°C) and (pH 7, 60°C, pH 6–11, 〈70°C), respectively. CHSA1 and CHSA2 had broad pH and thermal stability. CHSA1 and CHSA2 were both inhibited by EDTA and were inhibited completely by 5 mM Mn 2+ . CHSA1 and CHSA2 degraded chitosan with DD ranging from 60 to 98%, and also degraded some chitin. The most susceptible substrate was 60% deacetylated chitosan. Furthermore, TKU024 culture supernatant (1.5% SPP) incubated for 5 days has the most reducing sugars (0.63 mg/ml). With this method, we have shown that shellfish wastes may have a great potential for the production of bioactive materials. Content Type Journal Article Pages 1-10 DOI 10.1007/s10532-011-9453-5 Authors San-Lang Wang, Life Sciences Development Center, Tamkang University, Taipei, 25137 Taiwan Wan-Nine Tseng, Department of Chemistry, Tamkang University, Taipei, 25137 Taiwan Tzu-Wen Liang, Life Sciences Development Center, Tamkang University, Taipei, 25137 Taiwan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Different methods for determining the toxicity and biodegradability of hazardous compounds evaluating their susceptibility to biological treatment were studied. Several compounds including chlorophenols and herbicides have been evaluated. Toxicity was analyzed in terms of EC 50 and by a simple respirometric procedure based on the OECD Method 209 and by the Microtox ® bioassay. The values of EC 50 obtained from respirometry were in all the cases higher than those from the Microtox ® test. The respirometric inhibition values of chlorophenols were related well with the number of chlorine atoms and their position in the aromatic ring. In general, herbicides showed lower inhibition, being alachlor the less toxic from this criterion. For determination of biodegradability an easier and faster alternative to the OECD Method 301, with a higher biomass to substrate ratio is proposed. When this test was negative, the Zahn-Wellens one was performed in order to evaluate the inherent biodegradability. In the fast test of biodegradability, 4-chlorocatechol and 4-chlorophenol showed a complete biodegradation by an unacclimated sludge upon 48 h. These results together with their low respirometric inhibition, allow concluding that these compounds could be conveniently removed in a WWTP. Alachlor, 2,4-dichlorophenol, 2,4,6-trichlorophenol and MCPA showed a partial biodegradation upon 28 days by the Zahn-Wellens inherent biodegradability test. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-010-9448-7 Authors A. M. Polo, Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain M. Tobajas, Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain S. Sanchis, Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain A. F. Mohedano, Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain J. J. Rodríguez, Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The enrichment culture SL2 dechlorinating tetrachloroethene (PCE) to ethene with strong trichloroethene (TCE) accumulation prior to cis -1,2-dichloroethene ( cis -DCE) formation was analyzed for the presence of organohalide respiring bacteria and reductive dehalogenase genes ( rdhA ). Sulfurospirillum -affiliated bacteria were identified to be involved in PCE dechlorination to cis -DCE whereas “ Dehalococcoides ”-affiliated bacteria mainly dechlorinated cis -DCE to ethene. Two rdhA genes highly similar to tetrachloroethene reductive dehalogenase genes ( pceA ) of S. multivorans and S. halorespirans were present as well as an rdhA gene very similar to the trichloroethene reductive dehalogenase gene ( tceA ) of “ Dehalococcoides ethenogenes ” strain 195. A single strand conformation polymorphism (SSCP) method was developed allowing the simultaneous detection of the three rdhA genes and the estimation of their abundance. SSCP analysis of different SL2 cultures showed that one pceA gene was expressed during PCE dechlorination whereas the second was expressed during TCE dechlorination. The tceA gene was involved in cis -DCE dechlorination to ethene. Analysis of the internal transcribed spacer region between the 16S and 23S rRNA genes revealed two distinct sequences originating from Sulfurospirillum suggesting that two Sulfurospirillum populations were present in SL2. Whether each Sulfurospirillum population was catalyzing a different dechlorination step could however not be elucidated. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9454-4 Authors Julien Maillard, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Marie-Paule Charnay, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Christophe Regeard, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Emmanuelle Rohrbach-Brandt, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Katia Rouzeau-Szynalski, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Pierre Rossi, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Christof Holliger, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE—Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    A novel cellulolytic bacterium was isolated from the forest soil of KNU University campus. Through 16S rRNA sequence matching and morphological observation it was identified as Nocardiopsis sp. KNU. This strain can utilize a broad range of cellulosic substrates including: carboxymethyl cellulose (CMC), avicel, xylan, cellobiose, filter paper and rice straw by producing a large amount of thermoalkalotolerant endoglucanase, exoglucanase, xylanase and glucoamylase. Optimal culture conditions (Dubos medium, 37°C, pH 6.5 and static condition) for the maximal production of the cellulolytic enzymes were determined. The activity of cellulolytic and hemicelluloytic enzymes produced by this strain was mainly present extracellularly and the enzyme production was dependent on the cellulosic substrates used for the growth. Effect of physicochemical conditions and metal additives on the cellulolytic enzymes production were systematically investigated. The cellulases produced by Nocardiopsis sp. KNU have an optimal temperature of 40°C and pH of 5.0. These cellulases also have high thermotolerance as evidenced by retaining 55–70% activity at 80°C and pH of 5.0 and alkalotolerance by retaining 〉55% of the activity at pH 10 and 40°C after 1 h. The efficiency of fermentative conversion of the hydrolyzed rice straw by Saccharomyces cerevisiae (KCTC-7296) resulted in 64% of theoretical ethanol yield. Content Type Journal Article Pages 1-15 DOI 10.1007/s10532-010-9450-0 Authors Ganesh D. Saratale, Department of Biochemistry, Shivaji University, Kolhapur, Maharashtra 416004, India Sang Eun Oh, Bioenergy Laboratory, Department of Biological Environment, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, Gangwondo 200-701, South Korea Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    This study investigated the effects of organic fraction of municipal solid waste (OFMSW) addition on the anaerobic treatment of the olive-mill pomace. Biodegradability of olive-mill pomace mixed with OFMSW was examined in anaerobic bioreactors. Only OFMSW was loaded in the first (control) bioreactor, while run 1 and run 2 bioreactors included different ratio of OFMSW and olive-mill pomace. COD, BOD 5 , NH 4 –N, pH, VFA, CH 4 quantity and percentage in anaerobic bioreactors were regularly monitored. In addition, inert COD and anaerobic toxicity assay (ATA) were measured in leachate samples. The results of the study showed that 70% of OFMSW addition to olive-mill pomace has an advantage in terms of pollution parameters and methane generation. Since olive-mill pomace is not easy biodegradable, addition of high proportion of OFMSW promotes biodegradability of olive-mill pomace. Decreasing in BOD 5 /COD ratios in the run 1 and run 2 reactors carried out as 62 and 52%, respectively. Content Type Journal Article Pages 1-8 DOI 10.1007/s10532-010-9452-y Authors Osman Nuri Ağdağ, Environmental Engineering Department, Pamukkale University, Kinikli Campus, 20070 Denizli, Turkey Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Basic Violet 3 (BV) belongs to the most important group of synthetic colorants and is used extensively in textile industries. It is considered as xenobiotic compound which is recalcitrant to biodegradation. As Candida krusei could not use BV as sole carbon source, experiments were conducted to study the effect of cosubstrates on decolorization of BV in semi synthetic medium using glucose, sucrose, lactose, maltose, yeast extract, peptone, urea and ammonium sulphate. Maximum decolorization (74%) was observed in media supplemented with sucrose. Use of sugarcane bagasse extract as sole nutrient source showed 100% decolorization of BV within 24 h under optimized condition. UV–visible, FTIR spectral analysis and HPLC analysis confirmed the biodegradation of BV. Six degradation products were isolated and identified. We propose the biodegradation pathway for BV which occurs via stepwise reduction and demethylation process to yield mono-, di-, tri-, tetra-, penta- and hexa-demethylated BV species which was degraded completely. The study of the enzymes responsible for decolorization showed the activities of lignin peroxidase, lacasse, tyrosinase, NADH-DCIP reductase, MG reductase and azoreductase in cells before and after decolorization. A significant increase in activities of NADH-DCIP reductase and laccase was observed in the cells after decolorization. The yeast C. krusei could show the ability to decolorize the textile dye BV using inexpensive source like sugarcane bagasse extract for decolorization. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9472-2 Authors Charumathi Deivasigamani, Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, 632 014 Tamil Nadu, India Nilanjana Das, Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, 632 014 Tamil Nadu, India Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820