ALBERT

Description: In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non- Saccharomyces yeast species ( Lachancea thermotolerans , Metschnikowia pulcherrima , Hanseniaspora uvarum and Torulaspora delbrueckii ) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were alanine, arginine, asparagine, aspartic acid, glutamine, isoleucine, ammonium sulphate, serine, valine and mixtures of 19 amino acids and of 19 amino acids plus ammonium sulphate (for S. cerevisiae ), serine (for L. thermotolerans ), alanine (for H. uvarum ), alanine and asparagine (for M. pulcherrima ), arginine, asparagine, glutamine, isoleucine and mixture of 19 amino acids (for T. delbrueckii ). Furthermore, our results showed a clear positive effect of complex mixtures of N-sources on S. cerevisiae and on T. delbrueckii (although to a lesser extent) as to all performance parameters studied, whereas for L. thermotolerans , H. uvarum and M. pulcherrima , single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the influences of N-sources observed for T. delbrueckii and H. uvarum resembled those of S. cerevisiae the most and the least, respectively. Overall, this work contributes to an improved understanding of how different N-sources affect growth, glucose consumption and ethanol production of wine-related yeast species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during wine fermentations.

Description: Saccharopolyspora spinosa produces tetra-cyclic macrolide spinosyns, a group of highly efficient pesticidal agents. However, this species lacks efficient vectors for genetic manipulation. In this study, the circular plasmid pCM32 was newly isolated from Saccharopolyspora endophytica YIM 61095. The complete nucleotide sequence of pCM32 consists of 14,611 bp and is predicted to encode 17 open reading frames (ORFs). Interestingly, a putative int gene in pCM32 was predicted by homologous alignment to encode an integrase belonging to the tyrosine family of integrases/recombinases. Plasmid pCM238 containing this int locus derived from pCM32 could be transferred by conjugation from Escherichia coli into Sa. spinosa at a high frequency. Integration of pCM238 in the host chromosome was demonstrated as site-specific recombination (at the tRNA Ser gene) via a 56-bp core sequence within the attP / attB sites. Plasmid pCM265, a shuttle vector containing the int and attP sequences of pCM32, was constructed to introduce foreign genes into Sa. spinosa . The production of spinosad approximately doubled in Sa. spinosa NRRL18395 after introducing pCM265-derived plasmids carrying the genes for phosphofructokinase (PFK) or anthranilate synthase. These results indicate that plasmid pCM32 is an actinomycete integrative and conjugative element (AICE) and that its derived integrative vectors are useful for efficiently introducing foreign DNA into Sa. spinosa .

Description: Vibratory ball milling of cotton in the presence and absence of styrene was studied by electron paramagnetic resonance spectroscopy, gel permeation chromatography and ultraviolet resonance Raman (UVRR) spectroscopy. Mechanoradical formation in ball milling of cellulose was detected, but the radical content was significantly lower and the molar mass slightly higher in the presence of styrene. UVRR also showed a small but consistent increase in aromatic signal, even after 5 h acetone extraction. A small portion of styrene was attached to cellulose, which was observed as an increase in the aromatic band intensity. Stabilization or a slight increase in molar mass of the samples that were milled in the presence of styrene was also observed. Overall, under the studied conditions, ball milling is not sufficient to significantly polymerize styrene onto cellulose. For future trials of mechanochemical copolymerization, it is recommended that a vacuum or an inert atmosphere be used.

Description: In this work, Nannochloropsis salina was cultivated in a continuous-flow flat-plate photobioreactor, working at different residence times and irradiations to study the effect of the specific light supply rate on biomass productivity and photosynthetic efficiency. Changes in residence times lead to different steady-state cell concentrations and specific growth rates. We observed that cultures at steady concentration were exposed to different values of light intensity per cell. This specific light supply rate was shown to affect the photosynthetic status of the cells, monitored by fluorescence measurements. High specific light supply rate can lead to saturation and photoinhibition phenomena if the biomass concentration is not optimized for the selected operating conditions. Energy balances were applied to quantify the biomass growth yield and maintenance requirements in N. salina cells.

Description: An open reading frame CC1225 from the Caulobacter crescentus CB15 genome sequence belongs to the Gfo/Idh/MocA protein family and has 47 % amino acid sequence identity with the glucose-fructose oxidoreductase from Zymomonas mobilis ( Zm GFOR). We expressed the ORF CC1225 in the yeast Saccharomyces cerevisiae and used a yeast strain expressing the gene coding for Zm GFOR as a reference. Cell extracts of strains overexpressing CC1225 (renamed as Cc aaor ) showed some Zm GFOR type of activity, producing D-gluconate and D-sorbitol when a mixture of D-glucose and D-fructose was used as substrate. However, the activity in Cc aaor expressing strain was 〉100-fold lower compared to strains expressing Zm gfor . Interestingly, C. crescentus AAOR was clearly more efficient than the Zm GFOR in converting in vitro a single sugar substrate D-xylose (10 mM) to xylitol without an added cofactor, whereas this type of activity was very low with Zm GFOR. Furthermore, when cultured in the presence of D-xylose, the S. cerevisiae strain expressing Cc aaor produced nearly equal concentrations of D-xylonate and xylitol (12.5 g D-xylonate l −1 and 11.5 g D-xylitol l −1 from 26 g D-xylose l −1 ), whereas the control strain and strain expressing Zm gfor produced only D-xylitol (5 g l −1 ). Deletion of the gene encoding the major aldose reductase, Gre3p, did not affect xylitol production in the strain expressing Cc aaor , but decreased xylitol production in the strain expressing Zm gfor . In addition, expression of Cc aaor together with the D-xylonolactone lactonase encoding the gene xylC from C. crescentus slightly increased the final concentration and initial volumetric production rate of both D-xylonate and D-xylitol. These results suggest that C. crescentus AAOR is a novel type of oxidoreductase able to convert the single aldose substrate D-xylose to both its oxidized and reduced product.

Description: We have previously shown that overexpression of the human tumor suppressor protein P53 causes cell death of the yeast Saccharomyces cerevisiae . P53 overproduction led to transcriptional downregulation of some yeast genes, such as the TRX1/2 thioredoxin system, which plays a key role in cell protection against various oxidative stresses induced by reactive oxygen species (ROS). In the present work, the impact of TRX2 overexpression on apoptosis mediated by p53 overexpression in yeast is investigated. In yeast cells expressing P53 under an inducible promoter together with TRX2 under a strong constitutive promoter, we showed that Tr2p overproduction reduced the apoptotic effect exerted by P53 and increased the viability of the P53-overproducing cells. Furthermore, measurements of ROS amounts by flow cytometry and fluorescence microscopy indicated that the TRX2 protein acted probably through its increased detoxifying activity on the P53-generated ROS. The steady-state level and activity of P53 were not affected by TRX2 overexpression, as shown by western blotting and functional analysis of separated alleles in yeast (FASAY), respectively. The growth inhibitory effect of P53 was partially reversed by the antioxidant N -acetylcysteine. Our data strengthen the idea that overexpression of a single gene ( trx2 ) decreases the p53 -mediated cell death by decreasing ROS accumulation.

Description: The moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) is a novel solution to conventional activated sludge processes and membrane bioreactors. In this study, a pure MBBR-MBR was studied. The pure MBBR-MBR mainly had attached biomass. The bioreactor operated with a hydraulic retention time (HRT) of 9.5 h. The kinetic parameters for heterotrophic and autotrophic biomasses, mainly nitrite-oxidizing bacteria (NOB), were evaluated. The analysis of the bacterial community structure of the ammonium-oxidizing bacteria (AOB), NOB, and denitrifying bacteria (DeNB) from the pure MBBR-MBR was carried out by means of pyrosequencing to detect and quantify the contribution of the nitrifying and denitrifying bacteria in the total bacterial community. The relative abundance of AOB, NOB, and DeNB were 5, 1, and 3 %, respectively, in the mixed liquor suspended solids (MLSS), and these percentages were 18, 5, and 2 %, respectively, in the biofilm density (BD) attached to carriers. The pure MBBR-MBR had a high efficiency of total nitrogen (TN) removal of 71.81 ± 16.04 %, which could reside in the different bacterial assemblages in the fixed biofilm on the carriers. In this regard, the kinetic parameters for autotrophic biomass had values of Y A  = 2.3465 mg O 2  mg N −1 , μ m, A  = 0.7169 h −1 , and K NH  = 2.0748 mg N L −1 .

Description: Slow sand filtration (SSF) is an effective low-tech water treatment method for pathogen and particle removal. Yet despite its application for centuries, it has been uncertain to which extent pathogenic microbes are removed by mechanical filtration or due to ecological interactions such as grazing and competition for nutrients. In this study, we quantified the removal of bacterial faecal indicators, Escherichia coli and Enterococcus faecalis , from secondary effluent of a wastewater treatment plant and analysed the microbial community composition in compartments of laboratory model SSF columns. The columns were packed with different sand grain sizes and eliminated 1.6–2.3 log units of faecal indicators, which translated into effluents of bathing water quality according to the EU directive (〈500 colony forming units of E. coli per 100 ml) for columns with small grain size. Most of that removal occurred in the upper filter area, the Schmutzdecke . Within that same zone, total bacterial numbers increased however, thus suggesting a specific elimination of the faecal indicators. The analysis of the microbial communities also revealed that some taxa were removed more from the wastewater than others. These results accentuate the contribution of biological mechanisms to water purification in SSF.

Description: Pseudoalteromonas is widespread in various marine environments, and most strains can affect invertebrate larval settlement and metamorphosis by forming biofilms. However, the impact and the molecular basis of population diversification occurring in Pseudoalteromonas biofilms are poorly understood. Here, we show that morphological diversification is prevalent in Pseudoalteromonas species during biofilm formation. Two types of genetic variants, wrinkled (frequency of 12 ± 5 %) and translucent (frequency of 5 ± 3 %), were found in Pseudoalteromonas lipolytica biofilms. The inducing activities of biofilms formed by the two variants on larval settlement and metamorphosis of the mussel Mytilus coruscus were significantly decreased, suggesting strong antifouling activities. Using whole-genome re-sequencing combined with genetic manipulation, two genes were identified to be responsible for the morphology alternations. A nonsense mutation in AT00 _ 08765 led to a wrinkled morphology due to the overproduction of cellulose, whereas a point mutation in AT00 _ 17125 led to a translucent morphology via a reduction in capsular polysaccharide production. Taken together, the results suggest that the microbial behavior on larval settlement and metamorphosis in marine environment could be affected by the self-generated variants generated during the formation of marine biofilms, thereby rendering potential application in biocontrol of marine biofouling.

Description: This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2 %, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe 3+ and H + , which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe 3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function.

Description: A metagenomic fosmid expression library established from environmental DNA (eDNA) from the shallow hot vent sediment sample collected from the Levante Bay, Vulcano Island (Aeolian archipelago) was established in Escherichia coli . Using activity-based screening assays, we have assessed 9600 fosmid clones corresponding to approximately 350 Mbp of the cloned eDNA, for the lipases/esterases/lactamases, haloalkane and haloacid dehalogenases, and glycoside hydrolases. Thirty-four positive fosmid clones were selected from the total of 120 positive hits and sequenced to yield ca. 1360 kbp of high-quality assemblies. Fosmid inserts were attributed to the members of ten bacterial phyla, including Proteobacteria , Bacteroidetes , Acidobateria , Firmicutes , Verrucomicrobia , Chloroflexi , Spirochaetes , Thermotogae , Armatimonadetes , and Planctomycetes . Of ca. 200 proteins with high biotechnological potential identified therein, we have characterized in detail three distinct α/β-hydrolases (LIPESV12_9, LIPESV12_24, LIPESV12_26) and one new α-arabinopyranosidase (GLV12_5). All LIPESV12 enzymes revealed distinct substrate specificities tested against 43 structurally diverse esters and 4 p -nitrophenol carboxyl esters. Of 16 different glycosides tested, the GLV12_5 hydrolysed only p -nitrophenol-α-( l )-arabinopyranose with a high specific activity of about 2.7 kU/mg protein. Most of the α/β-hydrolases were thermophilic and revealed a high tolerance to, and high activities in the presence of, numerous heavy metal ions. Among them, the LIPESV12_24 was the best temperature-adapted, retaining its activity after 40 min of incubation at 90 °C. Furthermore, enzymes were active in organic solvents (e.g., 〉30 % methanol). Both LIPESV12_24 and LIPESV12_26 had the GXSXG pentapeptides and the catalytic triads Ser-Asp-His typical to the representatives of carboxylesterases of EC 3.1.1.1.

Description: Feruloyl or ferulic acid esterase (Fae, EC 3.1.1.73) catalyzes the hydrolysis of ester bonds between polysaccharides and phenolic acid compounds in xylan side chain. In this study, the thermostability of a type A feruloyl esterase (AuFaeA) from Aspergillus usamii was increased by iterative saturation mutagenesis (ISM). Two amino acids, Ser33 and Asn92, were selected for saturation mutagenesis according to the B-factors analyzed by B-FITTER software and ΔΔG values predicted by PoPMuSiC algorithm. After screening the saturation mutagenesis libraries constructed in Pichia pastoris , 15 promising variants were obtained. The best variant S33E/N92-4 (S33E/N92R) produced a T m value of 44.5 °C, the half-lives ( t 1/2 ) of 35 and 198 min at 55 and 50 °C, respectively, corresponding to a 4.7 °C, 2.33- and 3.96-fold improvement compared to the wild type. Additionally, the best S33 variant S33-6 (S33E) was thermostable at 50 °C with a t 1/2 of 82 min, which was 32 min longer than that of the wild type. All the screened S33E/N92 variants were more thermostable than the best S33 variant S33-6 (S33E). This work would contribute to the further studies on higher thermostability modification of type A feruloyl esterases, especially those from fungi. The thermostable feruloyl esterase variants were expected to be potential candidates for industrial application in prompting the enzymic degradation of plant biomass materials at elevated temperatures.

Description: Riemerella anatipestifer infection causes high mortality for ducks which results in major economic losses in the duck industry. In this study, we identified a mutant strain RA-M1 by Tn 4351 transposon mutagenesis, in which the M949_1603 gene encoding glycosyl transferase was inactivated. PCR analysis revealed that M949_1603 gene is specifically existed in R. anatipestifer serotype 1 strains. RA-M1 presented no reactivity to the anti-lipopolysaccharide (LPS) MAb in an indirect ELISA. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blotting demonstrated that RA-M1 LPS had a deficiency in ladder-like binding pattern to rabbit antiserum against R. anatipestifer serotype 1 strain CH3, indicating that the O-antigen structure of RA-M1 was changed. RA-M1 showed significant attenuated virulence in ducks and higher sensitivity to normal duck serum, compared with its parent strain CH3. Furthermore, cross-protection of RA-M1 for R. anatipestifer serotypes 1, 2, and 10 strains was evaluated. Ducks that received two immunizations with inactivated RA-M1 vaccine were 100 % protected from challenge with R. anatipestifer serotype 1 strain WJ4, serotype 2 strain Yb2, and serotype 10 strain HXb2. No changes were observed in the liver, heart, or spleen samples from the protected ducks during autopsy and histological examination. Furthermore, vaccination generated high antibody titers of 1:12,800 against serotypes 1, 2, and 10 strains and enhanced production of interleukin 2 (IL-2) and IL-4 in ducks. These results suggested that M949_1603 gene is associated with serotype 1 O-antigen biosynthesis, and mutant RA-M1 could be used as a novel cross-protection vaccine candidate to protect ducks against R. anatipestifer infection.

Description: Saccharopolyspora spinosa can produce spinosad as a major secondary metabolite, which is an environmentally friendly agent for insect control. Cobalamin-independent methionine synthase (MetE) is an important enzyme in methionine biosynthesis, and this enzyme is probably closely related to spinosad production. In this study, its corresponding gene metE was inactivated, which resulted in a rapid growth and glucose utilisation rate and almost loss of spinosad production. A label-free quantitative proteomics-based approach was employed to obtain insights into the mechanism by which the metabolic network adapts to the absence of MetE. A total of 1440 proteins were detected from wild-type and Δ metE mutant strains at three time points: stationary phase of Δ metE mutant strain (S1 Δ metE , 67 h), first stationary phase of wild-type strain (S1 WT , 67 h) and second stationary phase of wild-type strain (S2 WT , 100 h). Protein expression patterns were determined using an exponentially modified protein abundance index (emPAI) and analysed by comparing S1 Δ metE /S1 WT and S1 Δ metE /S2 WT . Results showed that differentially expressed enzymes were mainly involved in primary metabolism and genetic information processing. This study demonstrated that the role of MetE is not restricted to methionine biosynthesis but rather is involved in global metabolic regulation in S. spinosa .

Description: Chlorella vulgaris encapsulated in alginate beads were added into a bioreactor treating synthetic wastewater using Pseudomonas putida . A symbiotic CO 2 /O 2 gas exchange was established between the two microorganisms for photosynthetic aeration of wastewater. During batch operation, glucose removal efficiency in the bioreactor improved from 50 % in 12 h without aeration to 100 % in 6 h, when the bioreactor was aerated photosynthetically. During continuous operation, the bioreactor was operated at a low hydraulic retention time of 3.3 h at feed concentrations of 250 and 500 mg/L glucose. The removal efficiency at 500 mg/L increased from 73 % without aeration to 100 % in the presence of immobilized microalgae. The initial microalgae concentration was critical to achieve adequate aeration, and the removal rate increased with increasing microalgae concentration. The highest removal rate of 142 mg/L-h glucose was achieved at an initial microalgae concentration of 190 mg/L. Quantification of microalgae growth in the alginate beads indicated an exponential growth during symbiosis, indicating that the bioreactor performance was limited by oxygen production rates. Under symbiotic conditions, the chlorophyll content of the immobilized microalgae increased by more than 30 %. These results indicate that immobilized microalgae in symbiosis with heterotrophic bacteria are promising in wastewater aeration.

Description: Osteoporosis has been reported as a hidden death factor in aged people. So far, prevention and treatment therapies for osteoporosis only slow down the progress but do not treat the disease. Fucoidan has been recognized its roles in anti-tumor, anti-inflammatory, anti-coagulant and antiviral activities. To date, low molecular weight (LMW) fucoidan role in bone loss disease has been not determined yet. Therefore, this study aims to figure out potential effects of LMW fucoidan in osteoporosis in vitro and in vivo. LMW fucoidan was extracted from fresh Sargassum hemiphyllum showing a significant increase in 7F2 cell viability to 150.33 ± 6.50 % relative to normal fucoidan (130.12 ± 5.74 %). The expression of level BMP-2, ALP, osteocalcin significantly increased with 2.28 ± 0.06, 2.18 ± 0.12 and 2.06 ± 0.07 fold, respectively. The RT-PCR assay showed that LMW fucoidan increased mRNA expression of BMP-2, ALP, osteocalcin, COL I, BSP and osteonectin. Furthermore, the bone density and bone ash weight were considerably boosted by the oral administration of 280 mg/kg LMW fucoidan and 100 mg/kg calcium carbonate in C57BL/6J female aged mice. The present finding indicated that LMW fucoidan triggered osteogenic differentiation in vitro, and had an anabolic effect on bone mineralization in vivo. Dietary intake of LMW fucoidan from S. hemiphyllum suggested playing a role in the enhancement of bone loss with increasing age.

Description: The intestinal porcine epithelial cell line IPEC-J2 was used as an in vitro model to assess effects of additives on the adhesion and cell toxic effects of a F4-positive (ETEC) and a F4-negative Escherichia coli (DSM 2840) strain. Bacterial adhesion was examined using flow cytometry in IPEC-J2 cells infected with bacteria stained with 5,6-carboxymethyl fluorescein diacetate succinimidyl ester. Measurement of transepithelial electrical resistance (TEER) was performed to characterize the impact on IPEC-J2 monolayer integrity. The feed additives were prepared as aqueous extract and tested in different dilutions and incubation times. The F4-positive ETEC strain had a high adhesion to IPEC-J2 cells and reduced TEER shortly after the in vitro infection. The nonpathogenic E. coli strain DSM 2840 showed only low adhesion capacity and no TEER impairment. Infection with ETEC with added test extracts showed a reduction of bacterial adhesion to IPEC-J2 cells by an autolyzed yeast product ( p  〈 0.05). Bovine colostrum, an additive containing thyme extract and an organic acid mix did not interfere with the ETEC adherence. The TEER decrease of the IPEC-J2 monolayer after ETEC infection was not affected by the added substances. In conclusion, interference with epithelial adhesion might be a protective mechanism of the tested yeast extract, indicating that the cell culture model might be suitable as screening tool to complement in vivo challenge trials with piglets.

Description: This paper reports on a spectrophotometric method for rapidly determining the reactivity of dissolving pulps. After mercerization and xanthation, the dissolved cellulose fractions in the viscose dope were re-precipitated by acidification. This transmittance/absorbance of fibril suspension was measured by visible spectroscopy, showing a strong linear correlation (R 2  = 0.997) between the absorbance at 600 nm and the amount of the regenerated cellulose in the sample; i.e., the pulp reactivity. The results measured by the present method and those of the commonly used modified Fock method were in good agreement, with a relative difference of less than 11 %. In summary, the new method is rapid, simple, practical and suitable for use in determining the reactivity of dissolving pulps in laboratory or industrial applications.

Description: Esterification of fatty acids with glycerol is characterized by negligible solubility of the two liquid phases. The reactions to mono-, di- and triglycerides taking place in the fatty acid phase, are limited by chemical equilibrium. The scope of this study is to investigate in a tubular reactor the conversion of a homogeneous mixture of oleic acid and glycerol in tert -butanol. The liquid composition in this study was 1 mol of oleic acid, 6 mol of glycerol and 14 mol of tert -butanol. Experiments were conducted in a tubular reactor at 35 atm over a temperature range of 200–240 °C and residence times of 0.7–17.6 h to determine the kinetics and the chemical equilibrium. The selectivity to monoolein was 〉95 mol %. A reversible second order reaction fits the data well.

Description: Commercially available refined vegetable oils were investigated as calibration standards for the filtration device and protocol specified by ASTM D7501 for conducting the biodiesel cold soak filtration test. Filtration time was determined to be a function of the amount of vacuum applied during filtration, with an 8 % change in the filtration time of soybean oil occurring across the vacuum range specified by ASTM D7501. At a constant vacuum of 57 cm Hg the mean filtration time of 150 mL of soybean oil was independent of operator, device, and oil lot number. Mean filtration time was also largely independent of brand: the average of the mean filtration times of replicate samples of seven brands of soybean oil was 396 s with a minimum significant difference (MSD) of 28 s, and the filtration times of seven of eight brands of soybean oil tested fell within this MSD. Refined edible-grade corn, canola, peanut, safflower and sunflower oils gave reliable filtration times and would be suitable standards. Each oil exhibited a characteristic filtration time, all greater than that for soy oil. Filtration times were an approximately linear function of kinematic viscosities, as predicted by Darcy’s Law. Edible vegetable oils can serve as reliable, affordable, consistent and generally available materials for confirming the operability of the filtration device used in the biodiesel cold soak filtration test.

Description: The microbiological production of 2,3-butanediol (2,3-BDO) has attracted considerable attention as an alternative way to produce high-value chemicals from renewable sources. Among the number of 2,3-BDO-producing microorganisms, Klebsiella pneumoniae has been studied most extensively and is known to produce large quantity of 2,3-BDO from a range of substrates. On the other hand, the pathogenic characteristics of the bacteria have limited its industrial applications. In this study, two major virulence traits, outer core LPS and fimbriae, were removed through homologous recombination from 2,3-BDO-producing K. pneumoniae 2242 to expand its uses to the industrial scale. The K. pneumoniae 2242 ∆wabG mutant strain was found to have an impaired capsule, which significantly reduced its ability to bind to the mucous layer and evade the phagocytic activity of macrophage. The association with the human ileocecal epithelial cell, HCT-8, and the bladder epithelial cell, T-24, was also reduced dramatically in the K. pneumoniae 2242 ∆fimA mutant strain that was devoid of fimbriae. However, the growth rate and production yield for 2,3-BDO were unaffected. The K. pneumoniae strains developed in this study, which are devoid of the major virulence factors, have a high potential for the efficient and sustainable production of 2,3-BDO.

Description: Various food proteins including, e.g. gluten, collagen and casein are rich in l -proline residues. Due to the cyclic structure of proline, these proteins are well protected from enzymatic degradation by typical digestive enzymes. Proline-specific peptidases (PsP) belong to different families of hydrolases acting on peptide bonds (EC 3.4.x.x). They occur in various organisms including bacteria, fungi, plants and insects. Based on their biochemical characteristics, PsP type enzymes are further grouped into different subclasses of which prolyl aminopeptidases (EC 3.4.11.5, PAP), prolyl carboxypeptidases (EC 3.4.17.16, PCP) and prolyl oligopeptidases/prolyl endopeptidases (EC 3.4.21.26, POP/PEP) are of major interest for applications in food biotechnology. This mini review summarises the biochemical assays employed for these subclasses of PsP and their structural properties and the reaction mechanisms. A special focus was set on PsP derived from fungi and insects and important industrial applications in the field of food biotechnology. The degradation of gluten and collagen as well as the hydrolysis of bitter peptides are discussed.

Description: The paper describes the preparation of new probiotic formulations based on chitosan-coated alginate microcapsules containing three different probiotic strains, Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070, and Bifidobacterium animalis subsp. lactis PBS075 taken individually and as a mixture of them. The effects of microencapsulation on the viability of the strains in conditions simulating the gastrointestinal tract and under industrial processes conditions were studied. In addition, an evaluation of their probiotic properties was also investigated by in vitro tests on the human intestinal cell line HT-29 to explore the effect of microencapsulation on health beneficial effect of the considered strains. Non-encapsulated cells were completely destroyed when exposed to simulated gastric juice and other stress conditions, while encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice and heat and osmotic treatment. Moreover, in this study, the effect of the various microencapsulated probiotic strain formulations was compared with analogous formulations also containing the β-glucan Pleuran. The microencapsulation effectively protected the selected bacteria, as single strain and as a mixture of the three strains in both the formulations with and without Pleuran, from simulating gastrointestinal tract and industrial process conditions in delivering the viable cells without any significant adverse effect on their functionalities. The comparative study of the immunomodulatory properties of each single strain and the mixture of the three strains revealed a synergistic effect of the probiotic mixture, but no appreciable difference between the two kinds of formulations could be detected, as the effect of Pleuran is covered by the higher potential of the probiotic strains.

Description: Strategies for bioremediation of atrazine, a pesticide commonly polluting groundwater in low concentrations, were studied in two boreal nonagricultural soils. Atrazine was not mineralized in soil without bioremediation treatments. In biostimulation treatment with molasses, up to 52 % of atrazine was mineralized at 10 °C, even though the degradation gene copy numbers did not increase. Incubations with radioactively labeled atrazine followed by microautoradiographic analysis revealed that bioremediation strategies increased the relative proportion of active degraders from 0.3 up to 1.9 % of the total bacterial count. These results indicate that atrazine degradation might not solely be facilitated by atzA / trzN – atzB genes. In combined biostimulation treatment using citrate or molasses and augmentation with Pseudomonas citronellolis ADP or Arthrobacter aurescens strain TC1, up to 76 % of atrazine was mineralized at 30 °C, and the atrazine degradation gene numbers increased up to 10 7  copies g −1 soil. Clone libraries from passive samplers in groundwater monitoring wells revealed the presence of phylogenetic groups formerly shown to include atrazine degraders, and the presence of atrazine degradation genes atzA and atzB . These results show that the mineralization of low concentrations of atrazine in the groundwater zone at low temperatures is possible by bioremediation treatments.

Description: We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose using a nisin-controlled gene expression system in Lactococcus lactis . These polymers have potential for production of biodegradable gels, fibers, and films. We optimized production of DsrI using several different background vectors, signal peptides, strains, induction conditions, and bioreactor parameters to increase extracellular accumulation. Optimal production of the enzyme utilized a high-copy plasmid, pMSP3535H3, which contains a nisin immunity gene, L. lactis LM0230, and bioreactors maintained at pH 6.0 to stabilize the enzyme. We were able to significantly improve growth using the lactic acid inhibitor heme and by continuous removal of lactic acid with anion exchange resins, but enzyme production was less than the controls. The recombinant enzyme under optimized conditions accumulated in the culture medium to approximately 380 mg/L, which was over 150-fold higher compared to the native L. mesenteroides strain. Methods are also included for purification of DsrI utilizing the glucan-binding domain of the enzyme.

Description: Glutathione is a valuable tripeptide widely used in the pharmaceutical, food, and cosmetic industries. In industrial fermentation, glutathione is currently produced primarily using the yeast Saccharomyces cerevisiae . Intracellular glutathione exists in two forms; the majority is present as reduced glutathione (GSH) and a small amount is present as oxidized glutathione (GSSG). However, GSSG is more stable than GSH and is a more attractive form for the storage of glutathione extracted from yeast cells after fermentation. In this study, intracellular GSSG content was improved by engineering thiol oxidization metabolism in yeast. An engineered strain producing high amounts of glutathione from over-expression of glutathione synthases and lacking glutathione reductase was used as a platform strain. Additional over-expression of thiol oxidase (1.8.3.2) genes ERV1 or ERO1 increased the GSSG content by 2.9-fold and 2.0-fold, respectively, compared with the platform strain, without decreasing cell growth. However, over-expression of thiol oxidase gene ERV2 showed almost no effect on the GSSG content. Interestingly, ERO1 over-expression did not decrease the GSH content, raising the total glutathione content of the cell, but ERV1 over-expression decreased the GSH content, balancing the increase in the GSSG content. Furthermore, the increase in the GSSG content due to ERO1 over-expression was enhanced by additional over-expression of the gene encoding Pdi1, whose reduced form activates Ero1 in the endoplasmic reticulum. These results indicate that engineering the thiol redox metabolism of S. cerevisiae improves GSSG and is critical to increasing the total productivity and stability of glutathione.

Description: Baculoviruses have a long history of safe use as specific, environmentally friendly insecticides that provide alternatives to chemical pesticides for controlling insect pests. However, their use has been limited by several factors, particularly their slow pathogenicity. In this study, we constructed a recombinant Bombyx mori nucleopolyhedrovirus (BmNPV) and an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) that expressed an insect-specific cyto-insectotoxin (Cit1a) from the venom of the central Asian spider Lachesana tarabaevi . Cit1a is a comparatively long linear cytolytic molecule that contains a predicted α-helix structure composed of two short membrane-acting antimicrobial peptides (MAMPs) that are joined together in a “head-to-tail” shape. Cit1a fused to polyhedrin gene ( polh ) ( polh - cit1a ) was expressed in the nuclei as polyhedra in silkworm larvae, Bm5 and Sf9 cells. An early death of Bm5 and Sf9 cells by recombinant BmNPV/Polh-Cit1a and AcMNPV/Polh-Cit1a was observed compared with control viruses that lacked the toxin gene. The infected cells showed a loss of cytoplasm, membrane integrity, and structural changes, suggesting that recombinant baculovirus-infected cells were killed by the necrosis caused by Cit1a. In addition, the BmNPV/Polh-Cit1a showed a significant reduction in the median lethal time (LT 50 ) against silkworm larvae compared with those of control BmNPV that lacked the cit1a gene.

Description: Organic carbon, nitrogen, and sulfur are highly concentrated in municipal solid waste (MSW) landfill leachate, which usually frustrates conventional leachate treatment technologies from the perspective of energy costs. Therefore, the possibility of converting leachate to a new energy source via microbial fuel cell (MFC) technology has been examined recently. This paper summarizes the power output and energy recovery efficiency of the leachate-fed MFCs according to different feeding patterns, cell structures, and loading rates. Also, we assess potential energy-generating chemicals in leachate like nitrogen and sulfur compounds and propose alternative pathways, which may lift strict ratios between organic carbon and nitrogen content in conventional denitrification of leachate and are expected to achieve a higher voltage than traditional organic-oxygen based cells. Although currently power output of leachate-fed MFCs is limited, it seems well possible that dynamic characteristics of MSW leachates and microbial physiologies underlying some bio-electrochemically efficient activities (e.g., direct interspecies electron transfer) could be stimulated in MFC systems to improve the present status.

Description: Advancement in the field of cancer molecular biology has aided researchers to develop various new chemopreventive agents which can target cancer cells exclusively. Cancer chemopreventive agents have proficiency to inhibit, reverse and delay process of carcinogenesis during its early and later course. Chemopreventive agents can act as antioxidative, antimutagenic/antigenotoxic, anti-inflammatory agents or via aiming various molecular targets in a cell to induce cell death. Apoptosis is a kind of cell death which shows various cellular morphological alterations such as cell shrinkage, blebbing of membrane, chromatin condensation, DNA fragmentation, formation of apoptotic bodies etc. Nowadays, apoptosis is being one of the new approaches for the identification and development of novel anticancer therapies. For centuries, plants are known to play part in daily routine from providing food to management of human health. In the last two decades, diverse phytochemicals and various botanical formulations have been characterized as agents that possess potential to execute cancer cells via inducing apoptosis. Data obtained from the research carried out globally pointed out that natural products are the potential candidates which have capability to combat cancer. In the present review, we surveyed literature on natural products which throws light on the mechanism through which these phytochemicals induce apoptosis in cancer cells.

Description: Many filamentous fungi produce only conidia for dispersal and survival in vitro or in vivo. Here, we show that the developmental regulator WetA and the velvet protein VosA are not only required for conidial maturation but indispensable for conidiation in Beauveria bassiana , a filamentous entomopathogen. Deletion of wetA or vosA resulted in more than 90 % transcriptional depression of brlA and abaA , two activator genes in the central developmental pathway, during the critical period of conidiophore development and conidiation. Consequently, Δ wetA and Δ vosA strains lost 98 % in and 88 % of their conidiation capacities under optimal culture conditions, respectively. The conidia of Δ wetA showed more defective features than those of Δ vosA , including smaller size, lesser density, lower hydrophobicity, and impaired cell walls although intracellular trehalose content decreased more in the aging culture of Δ vosA than of Δ wetA . As a result, conidial sensitivity to cell wall perturbation was elevated in Δ wetA but unaffected in Δ vosA , which produced conidia more sensitive to the oxidant menadione and the wet-heat stress at 45 °C. Both deletion mutants showed similar defects in conidial tolerance to high osmolarity or UV-B irradiation but no change in conidial sensitivity to the other oxidant H 2 O 2 or the fungicide carbendazim. Moreover, Δ wetA lost more virulence to Galleria mellonella larvae than Δ vosA . All these phenotypical changes were restored by either wetA or vosA complementation. Taken together, WetA and VosA are indispensable for asexual development and contribute differentially to conidial quality and hence the biological control potential of B. bassiana against insect pests.

Description: This article examines the design of rotary-pulsating units intended for intensification of homogenization, dispersion, extraction, and absorption processes. The intensification and effectiveness of the processes is provided by interaction between forces of a different nature, which develop as a result of complexflow hydrodynamics, acoustic vibrations, and cavitation. Experimental investigations were conducted to determine optimal production and design parameters for implementation of these processes.

Description: A system capable of operating in downhole conditions at depths of several thousand meters is developed for measuring drilling engineering parameters (DEP) in real time. The aim is to monitor DEP during drilling, including the weight on the drill bit (WOB), torque on the drill bit (TOB), and lateral force on the drill bit. The design of the structure and parameters of the sensors, calibration of the sensors, and the field test results are described. Four separate strain gages and a measuring system are designed to measure DEP in the downhole during drilling in real time. The field tests show that the designs are sound. The measured axial force is greater than the calculated value, which means that the real WOB is higher than the logging WOB and the real TOB is greater than the logging torque. Thus, the survey instruments can meet the requirements for rotary steerable drilling and conventional drilling. The measured WOB and TOB data can also be used to analyze drill string vibrations.

Description: The key characteristics of a laboratory-scale membrane reformer for high-purity hydrogen production from methane with a 4- \( \mu \) m-thick palladium membrane are described quantitatively using a mathematical model for an ideal displacement reactor that takes account of the hydrogen mass flux through the membrane and chemical reaction in the gas phase. Application of model representations for calculating the basic technological and design parameters of a high-efficiency membrane reformer with a 41.8 m 3 H 2 /h production capacity for feeding a 50 kW battery of proton exchange membrane fuel cells (PEMFC) with hydrogen is illustrated on a project example.

Description: Uniform suspension of particulates (salt or spices) in oil-based marinades requires a gel behavior of the matrix. This can be achieved by adding a solid fat to the liquid oil. Besides rheology, appearance and thermal stability are important for the utilization as marinades. The influence of solid fat concentration ( c fat  = 2.5–5.5 wt%) and average cooling speed (1.4, 2.6, and 4.7 °C/min) on the functional properties of oil-fat gels from palm fat and canola oil was investigated. Oil-fat mixtures showed complex physiochemical behavior depending on the solid fat concentration and cooling rate. All samples had a shear-thinning behavior. Yield stresses and apparent viscosities increased at a constant cooling rate with increasing solid fat concentration. Frequency dependence of storage and loss modulus showed a transition from a viscous solution to a weak gel at c fat 〉 3.5 wt%. Samples at increasing cooling rates transitioned to weak gels at lower fat concentration (2.5 wt%). Mixtures became turbid and increasingly whiter as both solid fat concentration and cooling rates increased, which was explained by increased light-scattering by fat crystal aggregates. Results show the critical importance of proper formulation and preparation conditions on the functionality of oil-based marinades.

Description: Natural antioxidants to inhibit oxidation in edible oils are in high demand. Grape pomace is an abundant, inexpensive source of polyphenolic antioxidants, which are responsible for numerous health benefits. We examined pomace from eight varieties of Midwestern hybrid grapes for phenolic content and antioxidant activity. Ethanolic extracts produced from the pomace of each grape variety were added to two model systems, bulk soybean oil and oil-in-water emulsions, to determine antioxidant activity. Oxidation was monitored in each model system at a temperature appropriate to that particular system. While the extracts had relatively little effect in bulk oil, we observed dose-dependent antioxidant effects of some extracts in oil-in-water emulsions. Oxidation in bulk oils was assessed via total polar compounds and polymerized triacylglycerols. Oxidation in emulsions was assessed by peroxide value, headspace oxygen measurements, gas chromatography of headspace volatiles, and fatty acid analysis. Pomace extracts derived from red grapes generally outperformed those from white grapes, with the Marechal Foch variety showing high antioxidant activity at intermediate concentrations. At higher concentrations, Marechal Foch, Corot Noir, Frontenac, and Norton extracts showed promising antioxidant activity. This is the first report on antioxidant activity in an oil and emulsion setting for many of these grape varieties.

Description: The effect of chitosan with different molecular weights and other natural substances on dextransucrase (DSase) activity from a representative oral pathogen Streptococcus mutans was elucidated. Among other bioactive substances, amino-monosaccharides such as glucosamine, mannosamine, and galactosamine exerted the enzyme inhibitory activity over 95 % of DSase. The specified hydrolysates derived from the hydrolysis of high molecular weight chitosan (HMWC) designated to CTSN, CTSN-P, CTSN-B, and CTSN-S with different molecular weights ranging from 3 to 8 kDa showed the similar inhibitory activity toward DSase. Also, the hyaluronic acid (MW 8.9 kDa), sulfated chitin, and amino-monosaccharides demonstrated the significant activity, CTSN, CTSN-P, CTSN-B, and CTSN-S are of potent bioactive substances that can be prepared in the cheapest way compared with other molecules tested available for antibacterial agent useful for human oral health.

Description: Rifamycin is a broad-spectrum antimicrobial drug produced commercially by submerged fermentation where the yields are far less in comparison to its demand in human drug therapy. Addressing the need, sequential mutational strain improvement was carried using UV and EtBr that resulted in improved strain yielding rifamycin SV up to 4.32 g/L. Further optimization of six important fermentation factors was followed which include temperature, agitation, inoculum level, period of fermentation, inorganic nitrogen source and amino acids. For the first time, we report a maximum yield of 5.32 g/L of rifamycin SV. Among the amino acids, proline known for its slowest assimilation by Amycolatopsis mediterranei produced the highest improvement in antibiotic yields. Following mutational strain improvement and process optimization, a total of 3.8-fold increase in antibiotic titre was achieved. Following a conventional procedure of mutational strain improvement, highest yield of rifamycin SV was reported by optimizing submerged fermentation process.

Description: A new molecularly imprinted polymer (MIP), prepared by hispidin as the template molecule, was synthesized and applied as an adsorbent phase for solid phase extraction (SPE) to isolate and enrich hispidin from eight species of mushrooms. The optimization of synthesis and the adsorption behaviors of the MIPs were investigated in detail. In comparison with C 18 -SPE, MIP-SPE displayed high selectivity and good affinity for hispidin for extract of Phellinus igniarius. The antioxidant activity of the extracts after using the MIPs was evaluated by free radical scavenging activity, and inhibition of erythrocyte hemolysis, and lipid peroxidation. This developed method provided a rapid, selective, and effective approach for separation and enrichment of active compounds from the natural products.

Description: There is a need to verify the quality of organically produced olive oils and to compare them to conventional ones. The objective of this study was to assess possible differences in nutritional quality between agronomic practices in Picual and Hojiblanca olive oil varieties at different stages of olive ripeness. The results showed that organic versus conventional cultivation did not consistently affect acidity, peroxide index or spectrophotometric constants of the virgin olive oils considered in this study. On the contrary, phenol content, oxidative stability, tocopherol content and fatty acid composition were affected by the agronomical practices. Principal component analysis indicated that linolenic acid and β-tocopherol were mainly responsible for discriminating Hojiblanca organic oils, whereas total phenols, palmitoleic acid and α-tocopherol were the major contributors to differentiating Picual conventional oils. Lignoceric and stearic acids were related to oils from unripe and ripe olive fruits, respectively. Long-term experiments are required to confirm these results.

Description: In this study, the effect of high residual lignin (21 % w/w) on the thermal properties of cellulose nanofibrils and the performance of films made from these nanofibrils in aqueous environments have been explored for the first time. Individualised cellulose nanofibrils with diameter 〈100 nm were obtained from the mechanical fibrillation of bark residue fibers with high lignin content. The mass loss by thermal degradation started at a higher temperature of 306 °C for these nanofibrils compared to 278 °C for those fibrils with low amount of lignin (5 % w/w). The maximum rate of degradation occurred at a temperature of around 390 and 319 °C for high and low lignin containing nanofibrils, respectively. Such a high thermal stability for high lignin containing nanofibrils has never been reported for nanocellulose from any other studies. The films made from these high lignin nanofibrils showed lower water uptake and better wet mechanical properties compared to films made from low lignin containing cellulose nanofibrils. The high lignin nanofibril films retained 38 % of the dry strength properties, while the low lignin nanofibril films were able to retain only 9 % of dry strength.

Description: The aim of this study was to classify Turkish commercial extra virgin olive oil (EVOO) samples according to geographical origins by using surface acoustic wave sensing electronic nose (zNose™) and machine vision system (MVS) analyses in combination with chemometric approaches. EVOO samples obtained from north and south Aegean region were used in the study. The data analyses were performed with principal component analysis class models, partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA). Based on the zNose™ analysis, it was found that EVOO aroma profiles could be discriminated successfully according to geographical origin of the samples with the aid of the PLS-DA method. Color analysis was conducted as an additional sensory quality parameter that is preferred by the consumers. The results of HCA and PLS-DA methods demonstrated that color measurement alone was not an effective discriminative factor for classification of EVOO. However, PLS-DA and HCA methods provided clear differentiation among the EVOO samples in terms of electronic nose and color measurements. This study is significant from the point of evaluating the potential of zNose™ in combination with MVS as a rapid method for the classification of geographically different EVOO produced in industry.

Description: Vinyl chloride (VC), a known human carcinogen, is a common and persistent groundwater pollutant at many chlorinated solvent contaminated sites. The remediation of such sites is challenging because of the lack of knowledge on the microorganisms responsible for in situ VC degradation. To address this, the microorganisms involved in carbon assimilation from VC were investigated in a culture enriched from contaminated site groundwater using stable isotope probing (SIP) and high-throughput sequencing. The mixed culture was added to aerobic media, and these were amended with labeled ( 13 C-VC) or unlabeled VC ( 12 C-VC). The cultures were sacrificed on days 15, 32, and 45 for DNA extraction. DNA extracts and SIP ultracentrifugation fractions were subject to sequencing as well as quantitative PCR (qPCR) for a functional gene linked to VC-assimilation ( etnE ). The gene etnE encodes for epoxyalkane coenzyme M transferase, a critical enzyme in the pathway for VC degradation. The relative abundance of phylotypes was compared across ultracentrifugation fractions obtained from the 13 C-VC- and 12 C-VC-amended cultures. Four phylotypes were more abundant in the heavy fractions (those of greater buoyant density) from the 13 C-VC-amended cultures compared to those from the 12 C-VC-amended cultures, including Nocardioides , Brevundimonas , Tissierella , and Rhodoferax. Therefore, both a previously identified VC-assimilating genus ( Nocardioides ) and novel microorganisms were responsible for carbon uptake. Enrichment of etnE with time was observed in the heavy fractions, and etnE sequences illustrated that VC-assimilators harbor similar Nocardioides- like etnE . This research provides novel data on the microorganisms able to assimilate carbon from VC.

Description: As antibiotic resistance continues to spread globally, there is growing interest in the potential to limit the spread of antibiotic resistance genes (ARGs) from wastewater sources. In particular, operational conditions during sludge digestion may serve to discourage selection of resistant bacteria, reduce horizontal transfer of ARGs, and aid in hydrolysis of DNA. This study applied metagenomic analysis to examine the removal efficiency of ARGs through thermophilic and mesophilic anaerobic digestion using bench-scale reactors. Although the relative abundance of various ARGs shifted from influent to effluent sludge, there was no measureable change in the abundance of total ARGs or their diversity in either the thermophilic or mesophilic treatment. Among the 35 major ARG subtypes detected in feed sludge, substantial reductions (removal efficiency 〉90 %) of 8 and 13 ARGs were achieved by thermophilic and mesophilic digestion, respectively. However, resistance genes of aad A, mac B, and sul 1 were enriched during the thermophilic anaerobic digestion, while resistance genes of erythromycin esterase type I, sul 1, and tet M were enriched during the mesophilic anaerobic digestion. Efflux pump remained to be the major antibiotic resistance mechanism in sludge samples, but the portion of ARGs encoding resistance via target modification increased in the anaerobically digested sludge relative to the feed. Metagenomic analysis provided insight into the potential for anaerobic digestion to mitigate a broad array of ARGs.

Description: Yersinia pestis , an infectious bacterium that is a causative agent of plague, a disease which has been shown to be one of the most feared in history and which has caused millions of deaths. The capsule-like fraction 1 (F1) antigen expressed by Y. pestis is a known specific marker for the identification of the bacteria; therefore, the detection of F1 is important for Y. pestis recognition. In this study, a rapid, sensitive, and specific technique, the lateral flow assay (LFA), was successfully developed to detect Y. pestis by the recombinant F1 antigen. The assay that utilized an anti-F1 polyclonal antibody (Pab) to identify the bacteria was based on a double-antibody sandwich format on a nitrocellulose membrane. With the LFA method, 50 ng/ml of recombinant F1 protein and 10 5 CFU/mL of Y. pestis could be detected in less than 10 min. This assay also showed no cross-reaction with other Yersinia spp. or with some selected capsule-producing Enterobacteriaceae strains. Furthermore, detection of Y. pestis in simulated samples has been evaluated. The detection sensitivity of Y. pestis in various matrices was 10 5 CFU/mL, which was identical to that in PBS buffer. The results obtained suggest that LFA is an excellent tool for detection of Y. pestis contamination in an environment and hence can be used to monitor plague diseases when they emerge.

Description: Microbial production of biodiesel from renewable feedstock has attracted intensive attention. Biodiesel is known to be produced from short-chain alcohols and fatty acyl-CoAs through the expression of wax ester synthase/fatty acyl-CoA: diacylglycerol acyltransferase that catalyzes the esterification of short-chain alcohols and fatty acyl-CoAs. Here, we engineered Escherichia coli to produce various fatty alcohol acetate esters, which depend on the expression of Saccharomyces cerevisiae alcohol acetyltransferase ATF1 that catalyzes the esterification of fatty alcohols and acetyl-CoA. The fatty acid biosynthetic pathways generate fatty acyl-ACPs, fatty acyl-CoAs, or fatty acids, which can be converted to fatty alcohols by fatty acyl-CoA reductase, fatty acyl-ACP reductase, or carboxylic acid reductase, respectively. This study showed the biosynthesis of biodiesel from three fatty acid biosynthetic pathway intermediates.

Description: The aim of this paper is to contribute to an improved understanding of deformation mechanisms of paperboard in the deep drawing process with immediate compression which reaches the highest degree of formability. Experiments with different fiber types and material structures were conducted on a laboratory and pilot scale to determine the major material-related influences on the formability of paperboard. The different fiber type combinations were studied together with different additives. The results show that increased pore volume and fiber-to-fiber mobility significantly increase initial wrinkle height which is significant for the quality of the drawn three dimensional (3D) structure. A material structure consisting of a mixture of cellulose fibers and a low percentage of stiff regenerated cellulose or synthetic staple fibers in combination with alkyl ketene dimer or cationic wax as an additive leads to a wrinkle-free wall until a forming ratio (forming height divided by base diameter) of at least 0.22 is reached. Accordingly, the process can be broken down into three phases. In the first phase, the cellulosic structures are deformed or broken, and the material density is reduced due to fiber-to-fiber movement. Refining and wet pressing decrease pore volume, increase the number of bonds in the material, thereby obstructing fiber-to-fiber movement. In the second phase, wrinkles occur. The introduced bending stiffness index together with the tensile index provides an indication of the material behavior in these two phases. The third phase is a restructuring of the material structure and a fixation of wrinkles by creating new bonds in the limited wrinkle areas. The experiments indicate that refined fibers make significantly higher wrinkle strength possible and thus better fixation of the final 3D structure shape. Additives with low melting temperatures can also contribute to improved wrinkle strength even in a low mass percentage of 0.5 %.

Description: Cellulose chemical robustness still remains a burden for value-added compounds production from biomass. The goal of this study was to take profit of the synergetic effects of dilute acid treatment and microwaves for the hydrolysis of highly crystalline cellulose. Afterwards, the liquid phase obtained after this treatment was treated microbiologically to transform the hydrolyzed product, containing glucose, into lactic acid. The hydrolysis reaction was performed in a microwave reactor. The samples were irradiated for 30 min up to 4 h at 400 watts maintaining the temperature at 393 K. At the optimal conditions, 88 % of cellulose was hydrolyzed. Glucose was the main obtained product. Through bio-fermentation Lactobacillus delbrueckii converted selectively all the present glucose into 98 % optically pure d -lactic acid, without suffering any inhibition from the rest of hydrolyzed products. The combination of cellulose hydrolysis under microwave irradiation and bio-fermentation at the conditions performed in this study opens a new alternative route to obtain valuable chemical platform products from cellulose.

Description: Epidermal growth factor (EGF) ameliorates stress and prevents incomplete gastrointestinal development in early-weaned piglets in commercial swine farming. This study aimed to further analyze the biological activities of intracellularly expressed EGF (IE-EGF), extracellularly expressed EGF (EE-EGF), and tagged EGF (T-EGF) from Saccharomyces cerevisiae in early-weaned pigs. In this study, we assigned 24 pigs to each of 5 groups that were provided a basic diet (the control group) or a diet supplemented with empty vector-expressing S. cerevisia e [the INVSc1(EV) group], T-EGF-expressing S. cerevisiae [the INVSc1-TE(−) group], EE-EGF-expressing S. cerevisiae [the INVSc1-EE(+) group], or IE-EGF-expressing S. cerevisiae [the INVSc1-IE(+) group]. All treatments were delivered at a dose of 60 μg EGF/kg body weight (BW) everyday. All the piglets were sacrificed after 21 day to determine their physio-biochemical indexes, immune functions, and intestinal development. In the piglet experiments, recombinant S. cerevisiae survived throughout the intestinal tract. The BW and intestinal development (e.g., mean villous height, crypt depth, villous height:crypt depth ratio (IVR), and total protein, DNA, and RNA contents) of the piglets were significantly enhanced in the INVSc1-IE(+) group compared with the animals in the INVSc1-EE(+) and INVSc1-TE(−) groups ( P  〈 0.05). In addition, increased proliferating cell nuclear antigen (PCNA) staining was observed in the piglets that received the INVSc1-IE(+) treatment (approximately 80 %) compared with those that received the INVSc1-TE(−) (approximately 70 %) and INVSc1-EE(+) treatments (approximately 70 %). The levels of lactate dehydrogenase (LDH), creatine kinase (CK), alkaline phosphatase (ALP), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) were also significantly increased in the INVSc1-IE(+) group compared with the INVSc1-EE(+) and INVSc1-TE(−) groups ( P  〈 0.05). Furthermore, the proliferation of piglet enterocytes was also significantly stimulated by both IE-EGF and EE-EGF compared with T-EGF in vitro ( P  〈 0.05). Our data further demonstrate the previously reported hypothesis that IE-EGF is more suitable than EE-EGF or T-EGF for applications in early-weaned pigs.

Description: With the rapid development of molecular diagnostic techniques, there is a growing need for quality controls and standards with favorable properties to monitor the entire detection process. In this study, we describe a novel method to produce armored hepatitis B virus (HBV) and human papillomavirus (HPV) DNA for use in nucleic acid tests, which was confirmed to be stable, homogeneous, noninfectious, nuclease resistant, and safe for shipping. We demonstrated that MS2 bacteriophage could successfully package double-stranded DNA of 1.3-, 3-, 3.5-, and 6.5-kb length into viral capsids with high reassembly efficiency. This is the first application of RNA bacteriophage MS2 as a platform to encapsulate double-stranded DNA, forming virus-like particles (VLPs) which were indistinguishable from native MS2 capsids in size and morphology. Moreover, by analyzing the interaction mechanism of pac site and the MS2 coat protein (CP), we found that in addition to the recognized initiation signal TR-RNA, TR-DNA can also trigger spontaneous reassembly of CP dimers, providing a more convenient and feasible method of assembly. In conclusion, this straightforward and reliable manufacturing approach makes armored DNA an ideal control and standard for use in clinical laboratory tests and diagnostics, possessing prospects for broad application, especially providing a new platform for the production of quality controls for DNA viruses.

Description: Lipids are naturally derived products that offer an attractive, renewable alternative to petroleum-based hydrocarbons. While naturally produced long-chain fatty acids can replace some petroleum analogs, medium-chain fatty acid would more closely match the desired physical and chemical properties of currently employed petroleum products. In this study, we engineered Yarrowia lipolytica , an oleaginous yeast that naturally produces lipids at high titers, to produce medium-chain fatty acids. Five different acyl-acyl carrier protein (ACP) thioesterases with specificity for medium-chain acyl-ACP molecules were expressed in Y. lipolytica , resulting in formation of either decanoic or octanoic acid. These novel fatty acid products were found to comprise up to 40 % of the total cell lipids. Furthermore, the reduction in chain length resulted in a twofold increase in specific lipid productivity in these engineered strains. The medium-chain fatty acids were found to be incorporated into all lipid classes.

Description: Long-term stable cell growth and production of vindoline, catharanthine, and ajmalicine of cambial meristematic cells (CMCs) from Catharanthus roseus were observed after 2 years of culture. C. roseus CMCs were treated with β-cyclodextrin (β-CD) and methyl jasmonate (MeJA) individually or in combination and were cultured both in conventional Erlenmeyer flasks (100, 250, and 500 mL) and in a 5-L stirred hybrid airlift bioreactor. CMCs of C. roseus cultured in the bioreactor showed higher yields of vindoline, catharanthine, and ajmalicine than those cultured in flasks. CMCs of C. roseus cultured in the bioreactor and treated with 10 mM β-CD and 150 μM MeJA gave the highest yields of vindoline (7.45 mg/L), catharanthine (1.76 mg/L), and ajmalicine (58.98 mg/L), concentrations that were 799, 654, and 426 % higher, respectively, than yields of CMCs cultured in 100-mL flasks without elicitors. Quantitative reverse transcription (RT)-PCR showed that β-CD and MeJA upregulated transcription levels of genes related to the biosynthesis of terpenoid indole alkaloids (TIAs). This is the first study to report that β-CD induced the generation of NO, which plays an important role in mediating the production of TIAs in C. roseus CMCs. These results suggest that β-CD and MeJA can enhance the production of TIAs in CMCs of C. roseus , and thus, CMCs of C. roseus have significant potential to be an industrial platform for production of bioactive alkaloids.

Description: Mechanisms of glutathione (GSH) over-accumulation in mutant Saccharomyces cerevisiae Y518 screened by ultraviolet and nitrosoguanidine-induced random mutagenesis were studied. Y518 accumulated higher levels of GSH and l -cysteine than its wild-type strain. RNA-Seq and pathway enrichment analysis indicated a difference in the expression of key genes involved in cysteine production, the GSH biosynthesis pathway, and antioxidation processes. GSH1 , MET17 , CYS4 , GPX2 , CTT1 , TRX2 , and SOD1 and the transcriptional activators SKN7 and YAP1 were up-regulated in the mutant. Moreover, Y518 showed a dysfunctional respiratory chain resulting from dramatically weakened activity of complex III and significant elevation of intracellular reactive oxygen species (ROS) levels. The supplementation of antimycin A in the culture of the parent strain showed equivalent changes of ROS and GSH level. This study indicates that defective complex III prompts abundant endogenic ROS generation, which triggers an oxidative stress response and upregulation of gene expression associated with GSH biosynthesis. This finding may be helpful for developing new strategies for GSH fermentation process optimization or metabolic engineering.

Description: Prenyltransferases of the dimethylallyltryptophan synthase (DMATS) superfamily are involved in the biosynthesis of secondary metabolites and contribute as modification enzymes significantly to structural diversity of natural products. They show usually broad specificity toward their aromatic substrates with regiospecific prenylations on aromatic rings. However, most members of this superfamily exhibit a high specificity toward their prenyl donors and usually accept exclusively dimethylallyl diphosphate (DMAPP). Recently, several indole prenyltransferases from this family were also demonstrated to accept unnatural DMAPP analogs such as methylallyl, 2-pentenyl and benzyl diphosphate for alkylation, or benzylation of the indole ring. Partial or complete shift of the substitution position was observed for these enzymes. In this study, we report the acceptance of these DMAPP analogs by two tyrosine O -prenyltransferases TyrPT from Aspergillus niger and SirD from Leptosphaeria maculans for alkylation or benzylation of tyrosine and derivatives. NMR and mass spectrometry (MS) analyses of nine isolated enzyme products confirmed the regiospecific O- or N -alkylation or benzylation at position C-4 of the aromatic ring, which is the same prenylation position of these enzymes in the presence of DMAPP.

Description: Multipotent mesenchymal stem/stromal cells (MSCs) are of great interest to researchers because of the unique properties, such as enhanced proliferation, paracrine activity and multilineage differentiation. Their non-immunogenicity, in combination with immunomodulatory properties, opens up the opportunity for the allogeneic application of MSCs. The MSC immunomodulatory capacity is currently being actively studied in vitro using various experimental designs. However, the results are not always univocal. It was found that the outcome of the stromal/immune cell interaction depends on experimental conditions. In this review we considered the impact of different factors, such as the ratio of stromal/immune cells, interaction time, the path of immune cell activation, etc. on the MSC immunomodulation. We also accentuated the importance of local milieu, in particular, oxygen tension, for the realization of MSC immunosuppressive activity.

Description: Cellulose nanowhiskers (CNWs) prepared via TEMPO mediated oxidation are used as biodegradable filler in an epoxy matrix. Since CNWs are hydrophilic and epoxy is hydrophobic, amphiphilic block copolymer surfactants are employed to improve the interactions between the filler and the matrix. The surfactants used are Pluronics, a family of triblock copolymers containing two poly(ethylene oxide) blocks and one poly(propylene oxide) block. In this study, Pluronic L61 and L121 with molecular weight of 2000 and 4400 g/mol and hydrophilic to lipophilic balance of 3 and 1 respectively, are used and their effect on the dispersion of CNWs in epoxy is discussed. The hydrophilic tails of Pluronics interact with the hydroxyl and carboxylic groups on the CNW surface and then these surfactant-treated CNWs are directly incorporated into epoxy by high speed mixing. The dispersion state of the surfactant-treated CNWs in epoxy is assessed by rheological measurements and the mechanical properties of the resulting composites are characterized by tensile test and dynamic mechanical thermal analysis. The Pluronic L61 treated CNW/epoxy composites show the highest storage modulus at high temperatures (about 77 % increases) indicative of improved interfacial interactions between the CNWs and the epoxy matrix. Also, an increase of around 10 °C in the glass–rubbery transition temperature of the L61 treated CNW/epoxy composite leads to potential application at higher service temperatures.

Description: Polypyrrole/cellulose fiber-conductive composites were chemically synthesized in situ by using, for the first time, cationic polyacrylate copolymer as dopant and FeCl 3 as oxidant. The impacts of dopant charge density on the adsorption of the dopant on cellulose fiber, microstructure, tensile strength, conductivity and stability were investigated. In addition, the elemental composition, distribution and doping state of the polypyrrole in conductive fiber were determined by elemental analysis and X-ray photoelectron spectroscopy. Compared with anthraquinone-2-sulfonic acid sodium salt, cationic polyacrylate copolymer was a more effective dopant in increasing the conductivity and conductivity stability of conductive paper. The decay of mechanical properties was also weakened. The surface resistivity decreased from 4.6 to 0.3 KΩ square −1 with increasing dopant charge density from 0.525 to 0.820 μmol g −1 and then increased with a further increase in the dopant charge density. It was also found that the polypyrrole retention in conductive fiber reached the maximum when the charge density of the dopant was 0.820 μmol g −1 . When the conductive fiber was doped with high-charged dopant, polypyrrole was easier to enter into the fiber lumen, and bipoloran charge carriers were more easily formed. With respect to the conductive fibers prepared with dopant of 0.820 and 0.525 μmol g −1 charge density, the total content of polaron and bipolaron in the former conductive fiber was higher than the content of polaron in the latter conductive fiber. In addition, uniform and denser nanofibrous PPy can be formed by controlling the dopant charge density.

Description: Nutritional systems biology is an evolving research field aimed at understanding nutritional processes at a systems level. It is known that the development of cancer can be influenced by the nutritional status, and the link between vitamin D status and different cancer types is widely investigated. In this study, we performed an integrative network-based analysis using a publicly available data set studying the role of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) in prostate cancer cells on mRNA and microRNA level. Pathway analysis revealed 15 significantly altered pathways: eight more general mostly cell cycle-related pathways and seven cancer-specific pathways. The changes in the G1-to-S cell cycle pathway showed that 1,25(OH) 2 D 3 down-regulates the genes influencing the G1-to-S phase transition. Moreover, after 1,25(OH) 2 D 3 treatment the gene expression in several cancer-related processes was down-regulated. The more general pathways were merged into one network and then extended with known protein–protein and transcription factor–gene interactions. Network algorithms were used to (1) identify active network modules and (2) integrate microRNA regulation in the network. Adding microRNA regulation to the network enabled the identification of gene targets of significantly expressed microRNAs after 1,25(OH) 2 D 3 treatment. Six of the nine differentially expressed microRNAs target genes in the extended network, including CLSPN , an important checkpoint regulator in the cell cycle that was down-regulated, and FZD5 , a receptor for Wnt proteins that was up-regulated. The extendable network-based tools PathVisio and Cytoscape enable straightforward, in-depth and integrative analysis of mRNA and microRNA expression data in 1,25(OH) 2 D 3 -treated cancer cells.

Description: Linoleate 13-lipoxygenase from Burkholderia thailandensis was expressed in Escherichia coli for the production of 13-hydroxyoctadecadienoic acid (13-HODE), an antiseptic emulsifier. Linoleate 13-lipoxygenase in cells had higher thermal stability than the purified enzyme. To increase 13-HODE production, recombinant cells were permeabilized by solvents, detergents, salts, and other chemicals. The enzymatic activity in cells was the highest for permeabilized cells treated with 0.5 M NaCl among the permeabilizers tested. The optimal reaction conditions for the production of 13-HODE from linoleic acid by permeabilized cells treated with 0.5 M NaCl were at pH 7.5, 25 °C, 20 g/l linoleic acid, 15 g/l cells, 0.15 mM Cu 2+ , and 6 % (v/v) methanol in a 100-ml baffled flask containing a 5-ml working volume with agitation at 200 rpm. Under these conditions, permeabilized cells produced 15.8 g/l 13-HODE after 30 min with a conversion yield of 79 % (w/w) and a productivity of 31.6 g/l/h. The conversion yield and productivity of permeabilized cells for 13-HODE production were higher than those of purified and crude enzymes as well as nonpermeabilized cells. Therefore, permeabilized cells were efficient biocatalysts for 13-HODE production. To the best of our knowledge, this is the first report of the production of 13-HODE using cells.

Description: Isolates of Aspergillus species are able to produce a large number of secondary metabolites. The profiles of biosynthetic families of secondary metabolites are species specific, whereas individual secondary metabolite families can occur in other species, even those phylogenetically and ecologically unrelated to Aspergillus . Furthermore, there is a high degree of chemo-consistency from isolate to isolate in a species even though certain metabolite gene clusters are silenced in some isolates. Genome sequencing projects have shown that the diversity of secondary metabolites is much larger in each species than previously thought. The potential of finding even further new bioactive drug candidates in Aspergillus is evident, despite the fact that many secondary metabolites have already been structure elucidated and chemotaxonomic studies have shown that many new secondary metabolites have yet to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different genera Aspergillus , Dichotomomyces , Phialosimplex , Polypaecilum and Cristaspora . Secondary metabolites common between the subgenera and sections of Aspergillus are surprisingly few, but many metabolites are common to a majority of species within the sections. We call small molecule extrolites in the same biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites appear to have evolved because of ecological challenges rather than being inherited from ancestral species, at least when comparing the species in the different sections of Aspergillus . Within the Aspergillus sections, secondary metabolite pathways seem to inherit from ancestral species, but the profiles of these secondary metabolites are shaped by the biotic and abiotic environment. We hypothesize that many new and unique section-specific small molecule extrolites in each of the Aspergillus will be discovered.

Description: Application of disk springs as vibration isolators with quasi-zero stiffness is described. Analytical studies are made to determine the design parameters of the described vibration isolators. The model of a disk spring as a combination of a separate disk spring and an annular section is proposed.

Description: The hybrid nanocomposite material of bacterial cellulose (BC) nanofibers and titaniumdioxide (TiO 2 ) nanoparticles with improved visible light sensitivity was developed by doping nitrogen (N) and fluorine (F) on TiO 2 nanoparticles embedded on BC nanofibers. To synthesize TiO 2 nanoparticles on BC produced by Acetobacter xylinum (TISTR 975), titanium tetraisopropoxide (TTIP) was used as a titanium source and was directly hydrolyzed on BC nanofibers. After providing heat via the reflux technique to BC/TiO 2 pellicle, the crystalline structure of TiO 2 was changed to an anatase form on a three dimensional network structure of BC confirmed by XRD. Nitrogen (N) and fluorine (F) were successfully doped into TiO 2 nanoparticles by using NH 4 F as the source of N and F (BC/N–F-co-doped TiO 2 ). The TEM results showed that the average particle size of BC/N–F-co-doped TiO 2 was smaller than the BC matrix containing none of the co-doped TiO 2 (BC/TiO 2 ) and N-doped TiO 2 (BC/N–TiO 2 ). In addition, BC/N–F-co-doped TiO 2 demonstrated the high efficiency of photocatalytic disinfection activity against both gram-negative and gram-positive bacteria under fluorescence light. Nevertheless, the photocatalytic antibacterial activity of N–F-co-doped TiO 2 also depended on the type of bacteria, and degree of N–F-co-doped TiO 2 .

Description: The probabilistic criterion of assessment of fi re safety of oil and gas industrial facilities exposed to the influence of active forest fires in the adjoining area is examined. Various scenarios of thermal effect of forest fires on constructional materials of industrial facilities are described. The function of the criterion is demonstrated using a simplified deterministic thermophysical constructional material ignition model. The results of model calculations of the probability of occurrence of fire at industrial facilities are reported.

Description: The possibility of predicting motor oil behavior at high and low (moderate) temperatures is shown, and based on this a model that allows prediction of deposit forming tendency of oil at high (HTD) and low (LTD) temperatures is built within the framework of formulation of a physicomechanical (or motochemical) approach. The specific nature of HTD and LTD formation is associated with the peculiarities of disperse phase behavior, which is realized in various degrees of filling of the phase surface by oil additives and is expressed in the difference of temperature stability of surface (protective) layers.

Description: Gene amplification using dihydrofolate reductase gene ( dhfr ) and methotrexate (MTX) is widely used for recombinant protein production in mammalian cells and is typically conducted in DHFR-deficient Chinese hamster ovary (CHO) cell lines. Generation of DHFR-deficient cells can be achieved by an expression vector incorporating short hairpin RNA (shRNA) that targets the 3′-untranslated region (UTR) of endogenous dhfr . Thus, shRNAs were designed to target the 3′-UTR of endogenous dhfr , and shRNA-2 efficiently down-regulated dhfr expression in CHO-K1 cells. A single gene copy of shRNA-2 also decreased the translational level of DHFR by 80 % in Flp-In CHO cells. shRNA-2 was then incorporated into a plasmid vector expressing human erythropoietin (EPO) and an exogenous DHFR to develop EPO-producing cells in the Flp-In system. The specific EPO productivity ( q EPO ) was enhanced by stepwise increments of MTX concentration, and differences in the amplification rate were observed in Flp-In CHO cells that expressed shRNA-2. In addition, the q EPO increased by more than 2.5-fold in the presence of 500 nM MTX. The mRNA expression level and gene copy numbers of dhfr were correlated with increased productivity in the cells, which is influenced by inhibition of endogenous dhfr . This study reveals that an expression vector including shRNA that targets the 3′-UTR of endogenous dhfr can enhance the transgene amplification rate and productivity by generating DHFR-deficient cells. This approach may be applied for amplifying the foreign gene in wild-type cell lines as a versatile single-plasmid vector.

Description: A comparison of the pressure characteristics of constant- and variable-lead screws obtained experimentally and computed on the basis of geometric parameters in light of reverse currents is carried out. Good convergence of the computed pressure characteristics of the screws with the experimental values is demonstrated. A graph of the dependence of the basic parameters of a screw, such as the maximum head, capacity, and efficiency, on the ratio between the blade spacing at the inlet and at the outlet, is presented.

Description: It is shown that introduction into electrodes and agglomerated fluxes for arc welding of ultrafine refractory compound components facilitates an increase in low-carbon steel metal structure cold resistance.

Description: Experimental and full-scale pilot tests of a newly developed thermoacoustic down-hole system and a combined technology in fields of Western Siberia and the Samara Oblast testify to their high efficiency. The equipment and technology developed can be offered to oil companies to increase the yield of their wells.

Description: Biological activities of medicinal mushrooms have been attributed to β-(1→3),(1→6)-glucans that are present in the cell wall of fungi and some plants. Antitumor, immunomodulatory, antimicrobial, antinociception, antiinflammatory, prebiotic, antioxidant, and antidiabetic are some of different properties already described for β-(1→3),(1→6)-glucans. Immune activation systems, including specific β-glucan receptors like Dectin-1, complement (CR3), and Toll (TLR), have been identified to clarify these biological effects. The β-(1→3)-glucans are synthesized by β-(1→3)-glucan synthase (GLS), an enzyme belonging to the glucosyltransferase group, which has a catalytic unit (FKS) and another regulatory (RHO). The mechanisms for adding β-(1→6) branches to the non-reducing ends of the β-(1→3)-glucan chains are unclear until now. Due to the biological importance of β-(1→3),(1→6)-glucan, it is necessary to understand the biochemical and molecular mechanisms of its synthesis, both to optimize the production of bioactive compounds and to develop antifungal drugs that interrupt this process. Therefore, the aim of this review is to gather information about the potential of β-(1→3),(1→6)-glucans, their methods of isolation, purification, and chemical characterization, as well as how these biomolecules are synthesized by fungi and what studies involving biotechnology or molecular biology have contributed to this subject.

Description: The interaction of copper ions with chitosan and three synthesized derivatives with different chelating centers, N -benzylidene chitosan, N -benzyl chitosan and poly- N -(4-(4- R -methoxyphenyl)diazenyl)-benzyl-chitosan using CuSO 4 ·5H 2 O and CuCl 2 ·2H 2 O salts was studied. The content of Cu 2+ in the complexes was determined by atomic absorption spectrometry and the results showed that chitosan exhibited higher chelating capacity for both salts. Morphological changes of derivatives and complexes were demonstrated by SEM–EDS. In addition, the presence of some crystals attributed to copper sulfate adsorbed on the polymer surface was also observed, which indicates that part of the metal content is in the salt adsorbed and might influence in the use of the materials for further application studies. This result was supported by Raman spectroscopy results in which vibrations of O=S=O groups were observed. X-ray diffraction patterns showed that the chemical modification of chitosan and formation of complexes resulted in the decrease of crystallinity. Electron paramagnetic resonance was used to investigate structural aspects of the materials complexed with Cu 2+ ions in the solid state.

Description: Novel bio-polyamides obtained from renewable resources, e.g. PA4.10, are considered nowadays as promising ‘green’ engineering materials consisting of building blocks derived from castor oil. In this work the composites of heterogeneously acetylated microfibrillated cellulose (MFC) and biopolyamide 4.10 have been prepared by melt blending. Thermoplastic processing of PA4.10/MFC composites was possible in a narrow temperature window due to significant improvement of thermal stability of acetylated MFC as compared to raw MFC. The increase of thermooxidative stability of filler was due to removal of non-cellulosic components from the raw material and introduction of acetic moieties that had additional slight stabilizing effect on MFC. Moreover, the modified MFC showed significant changes in morphology that favoured its dispersibility in viscous polymer melt. Combined treatment of MFC by chemical agents, which caused partial hydrolysis of amorphous regions, and physical disintegration by ultrasonic waves resulted in formation of fibrous material with low degree of entanglement and submicron or nanometric diameters. In the tested range of screw speeds it was found that at screw speed of 100 rpm the shearing forces were sufficient for dispersing MFC agglomerates and the melt pressure secured evacuation of gases introduced to plasticizing system of extruder with MFC-Ac aerogel. The dynamic mechanical properties of obtained (nano)composites were influenced by both mechanical strengthening of rigid cellulose micro and nanofibers as well as susceptibility of biopolymers towards oxidation and thermomechanical degradation during processing.

Description: Bluetongue virus (BTV) is the causative agent of bluetongue (BT), an important sheep disease that caused great economic loss to the sheep industry. There are 26 BTV serotypes based on the outer protein VP2. However, the serotypes BTV-1 and BTV-16 are the two most prevalent serotypes in China. Vaccination is the most effective method of preventing viral infections. Therefore, the need for an effective vaccine against BTV is urgent. In this study, DNA vaccines and recombinant fowlpox virus (rFPV) vaccines expressing VP2 alone or VP2 in combination with VP5 or co-expressing the VP2 and VP5 proteins of BTV-1 were evaluated in both mice and sheep. Several strategies were tested in mice, including DNA vaccine prime and boost, rFPV vaccine prime and boost, and DNA vaccine prime and rFPV vaccine boost. We then determined the best vaccine strategy in sheep. Our results indicated that a strategy combining a DNA vaccine prime (co-expressing VP2 and VP5) followed by an rFPV vaccine boost (co-expressing VP2 and VP5) induced a high titer of neutralizing antibodies in sheep. Therefore, our data suggest that a DNA vaccine consisting of a pCAG-(VP2+VP5) prime and an rFPV-(VP2+VP5) boost is an important candidate for the design of a novel vaccine against BTV-1.

Description: Numerous species of wild-grown mushrooms are among the most vulnerable organisms for contamination with radiocesium released from a radioactive fallout. A comparison was made on radiocesium as well as the natural gamma ray-emitting radionuclide ( 40 K) activity concentrations in the fruiting bodies of several valued edible Boletus mushrooms collected from the region of Europe and Yunnan Province in China. Data available for the first time for Boletus edulis collected in Yunnan, China, showed a very weak contamination with 137 Cs. Radiocesium concentration activity of B. edulis samples that were collected between 2011 and 2014 in Yunnan ranged from 5.2 ± 1.7 to 10 ± 1 Bq kg −1 dry matter for caps and from 4.7 ± 1.3 to 5.5 ± 1.0 Bq kg −1 dry matter for stipes. The mushrooms Boletus badius , B. edulis , Boletus impolitus , Boletus luridus , Boletus pinophilus , and Boletus reticulatus collected from the European locations between 1995 and 2010 showed two to four orders of magnitude greater radioactivity from 137 Cs compared to B. edulis from Yunnan. The nuclide 40 K in B. badius was equally distributed between the caps and stipes, while for B. edulis , B. impolitus , B. luridus , B. pinophilus , and B. reticulatus , the caps were richer, and for each mushroom, activity concentration seemed to be more or less species-specific.

Description: A novel TaqMan-based multiplex real-time PCR method combined with propidium monoazide (PMA) treatment was firstly developed for the simultaneous quantification of viable Vibrio parahaemolyticus and Listeria monocytogenes in raw shrimp. The optimization of PMA concentration showed that 100 μM was considered optimal to effectively inhibit 10 8  CFU/mL dead cells of both bacteria. The high specificity of this method was confirmed on tests using 96 target and non-target strains. The optimized assay could detect as low as 10 1 –10 2  CFU/g of each strain on the artificially contaminated shrimp, and its amplification efficiencies were up to 100 and 106 % for V. parahaemolyticus and L. monocytogenes , respectively. Furthermore, this assay has been successfully applied to describe the behavior of these two pathogens in raw shrimps stored at 4 °C. In conclusion, this PMA TaqMan-based multiplex real-time PCR technique, where the whole procedure takes less than 5 h, provides an effective and rapid tool for monitoring contamination of viable V. parahaemolyticus and L. monocytogenes in seafood, improving seafood safety and protecting public health.

Description: A hybrid airlift reactor was adopted to retain aerobic granules in the reactor successfully for continuous operation. It was found that aerobic granules maintained excellent physical structure stability in the continuous-flow reactor with reactor performance as good as batch operation. However, flocs appeared after batch operation was switched to continuous operation, and chemical oxygen demand (COD) in the wastewater was thus removed by co-existed granules and flocs in the reactor. Furthermore, excessive precipitation of CaCO 3 as needled shaped aragonite in the continuous aerobic granular sludge reactor was observed, which led to the further enhancement of settling ability of granules with sludge volume index (SVI) reduction from 32 to 2 ml g −1 but specific oxygen utilization rate (SOUR) decrease from 61 to 23 mg O 2  g −1 MLVSS h −1 . Thus, apart from the physical structure stability, bioactivity stability of granules should be also considered as an important parameter to evaluate the continuous operation of aerobic granular sludge. Furthermore, the decrease in granule polysaccharide content implied that protein was more important for aragonite precipitation. The excessive aragonite precipitation in the continuous-flow reactor could be due to the competition between flocs and granules. In addition, the degradation of polysaccharide in aerobic granules under a continuous-flow mode may also contribute to excessive aragonite precipitation.

Description: Asphaltenes of various heavy oil resids are oxidized by aqueous sodium percarbonate solutions at 200°C and 4 MPa pressure. The composition and properties of the obtained products are analyzed. Water-soluble oxidation products in the asphaltene oxidation products comprise 47.4-49.4%. Products of oxidative condensation of asphaltenes enriched with hydroxyl, ether, and carboxyl groups dominate in the composition of water-insoluble oxidation products. The water-soluble oxidation products represent carboxylic acid concentrate. The characteristics of the structural-group composition of the obtained oxidation products are disclosed. The possibility of practical utilization of asphaltene oxidation products as adhesion additives to road asphalt and for removal of phenol from water is demonstrated.

Description: Apparent kinetic parameters of carbon dioxide sorption from biogas using solutions produced by suspending calcined dolomite are given. The optimum and effective CO 2 absorption temperature is 20°C. Kinetic calculations show that the apparent absorption order and the apparent absorption rate constant decrease with a rise of temperature. It is shown that the CO 2 absorption rate is a direct function of CO 2 partial pressure and an inverse function of temperature. A dolomite solution obtained by filtration of a 1% dolomite suspension in water is recommended for CO 2 absorption.

Description: Experiments were performed on catalytic hydrogen-free upgrading of low-octane gasoline fractions on zeolite-containing catalysts with various silicate moduli. Chromatographic analysis showed the influence of a change in the molecular-sieve characteristics of zeolite-containing catalysts on the individual and group composition of the obtained gasolines. It was found to be expedient to combine zeolite-containing catalysts with various silicate moduli in the catalyst composite in order to increase the conversion of the feedstock fraction.

Description: Gamma (γ-T3) and delta (δ-T3) tocotrienols are the most potent natural protective agents against harmful effects of radiation exposure and there is substantial interest in advancing these tocols toward Food and Drug Administration approval. However, co-administration with alpha tocopherol is reported to interfere with the radioprotective properties of the tocotrienols. The objective of this study was to test various flash chromatography conditions for the purification of fractions with a high proportion of γ-T3 or δ-T3 and a minimal amount of alpha isomers from tocol extract obtained from rice bran oil deodorizer distillate (RBODD). Load size (0.125, 0.250, 0.500 and 1.000 g), sample cartridge type (pre-packed silica cartridge, empty cartridge+Celite 545) and mobile phase gradient [varying proportions of hexane–acetic acid (99.1:0.9 v/v) and ethyl acetate–acetic acid (99.1:0.9 v/v)] were evaluated. Peak resolution was best with a load size of ~1 % column capacity and a 5-g silica sample cartridge coupled with a 12-g silica column. A linear gradient of 0.8 % ethyl acetate–acetic acid (99.1:0.9 v/v) to hexane–acetic acid (99.1:0.9 v/v) (50 min )  → 100 % ethyl acetate–acetic acid (99.1:0.9 v/v) (5 min) resulted in the best separation of tocols. The method developed was used to isolate tocols from samples of crude RBODD, tocol concentrate and tocol-rich extract. The use of these conditions with a tocol-rich extract resulted in several fractions containing 100 % purities of both γ-T3 and δ-T3.

Description: Oil and phenolics were extracted from Descurainia sophia (Sophia) seeds by a supercritical CO 2 system. Extractions were conducted in two sequential steps, first using 100 % CO 2 and then adding 10 % ethanol as co-solvent. The extracts were collected in each step using two separate collectors operating at different pressures. The extraction run was 3 and 4 h for the first period, and 2 h for the second period. The majority of the oil was collected in the first extraction period while phenolic compounds were obtained in the second extraction period. A combined mode of static/dynamic extraction (3 h running and 1 h soaking in CO 2 ) was also used in the first extraction period, which enhanced the total extraction yield (29.3 ± 0.5 %) and was comparable to the 4 h extraction yield (31.4 ± 0.1 %). The total fatty acid (FA) content of oil in collector 1 (0.94 g) was nearly twice that in collector 2 (0.60 g). The oil contained 14 FAs with α-linolenic being predominant (48.5 %), with a total 91.1 % unsaturated FAs, a ω3/ω6 ratio of 2.7, and an erucic acid content of 6.2 %. More than 10 phenolic compounds were detected by HPLC in the Sophia seed extracts of which sinapic acid was the dominant compound. Sophia seed extracts showed high levels of antioxidant activity. These results suggest that Sophia seed oil and phenolics have the potential for functional food and pharmaceutical applications.

Description: Venom, the mucus layer covering the body surface, ink glands, mammary glands, milk, and various animal secretory functions as both a physical and chemical defense barrier against bacteria and virus infections. Previously, several studies reported that l -amino acid oxidases (LAAOs) present in animal secretary fluids have strong antimicrobial activities and selective cytotoxic activities against Gram-positive and Gram-negative bacteria, various pathogenic bacteria, viruses, and parasite species. These LAAOs catalyze oxidative deamination of an l -amino acid substrate with the generation of hydrogen peroxide. The antibacterial activity of LAAOs is completely inhibited by catalase; thus, LAAOs kill bacteria by the hydrogen peroxide generated from the oxidation of l -amino acid substrates. This review focuses on the selective, specific, and local antibacterial actions of various LAAOs that may be used as novel therapeutic agents against infectious diseases. LAAOs that are suitable leads for combating multidrug-resistant bacterial infections are also studied.

Description: Results are presented for experimental investigations of pressure loss in a cylindrical duct with sudden section enlargement and interaction between an axial gas cross-flow and several rows of radial gas jets. The influence exerted by basic structural parameters, and also the velocities of the axial cross-flow and jets on hydraulic characteristics of the process is examined.

Description: A new design of a reciprocating compressor with intensive cooling of the cylinder-piston group based on an analysis of the cooling of reciprocating compressors is considered. Using the fundamental laws of conservation of energy, mass, and volume as well as the dynamical equation, equation of state, and Hooke’s equation, a mathematical model of the workflows is developed. Workflows in the reciprocating compressor being considered here with intensive cooling of the cylinder-piston group are analyzed and evaluated.

Description: Operation of a mixer-ejector in the cavitation mode is investigated. An analytical expression for the dimensionless pressure-capacity curve of the cavitational mixer-ejector is derived. The limiting allowable characteristics permitting analysis of the unit are obtained for known physical properties of the components of the mixture and their volume fractions within the flow of the mixture. An example is cited for analysis of a cavitational mixer-ejector.

Description: Experiments were designed to validate the two common DNA extraction protocols (CTAB-based method and DNeasy Blood & Tissue Kit) used to effectively recover actinobacterial DNA from sponge samples in order to study the sponge-associated actinobacterial diversity. This was done by artificially spiking sponge samples with actinobacteria (spores, mycelia and a combination of the two). Our results demonstrated that both DNA extraction methods were effective in obtaining DNA from the sponge samples as well as the sponge samples spiked with different amounts of actinobacteria. However, it was noted that in the presence of the sponge, the bacterial 16S rRNA gene could not be amplified unless the combined DNA template was diluted. To test the hypothesis that the extracted sponge DNA contained inhibitors, dilutions of the DNA extracts were tested for six sponge species representing five orders. The results suggested that the inhibitors were co-extracted with the sponge DNA, and a high dilution of this DNA was required for the successful PCR amplification for most of the samples. The optimized PCR conditions, including primer selection, PCR reaction system and program optimization, further improved the PCR performance. However, no single PCR condition was found to be suitable for the diverse sponge samples using various primer sets. These results highlight for the first time that the DNA extraction methods used are effective in obtaining actinobacterial DNA and that the presence of inhibitors in the sponge DNA requires high dilution coupled with fine tuning of the PCR conditions to achieve success in the study of sponge-associated actinobacterial diversity.

Description: Bacterial cell envelope is generally accepted as the primary target for a photo-induced oxidative stress. It is plausible that DNA damage occurs during the antimicrobial photoinactivation. Here we investigate the correlation between DNA damage and photoinactivation by evaluating the level of RecA-based DNA repair system in Staphylococcus aureus . By using exogenous photosensitizers (new methylene blue (NMB), toluidine blue O (TBO), 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra( p -toluenesulfonate) (TMPyP), zinc phthalocyanine (ZnPc), Rose Bengal (RB)) and ALA-induced endogenous porphyrin-dependent blue light (405 nm), several outcomes were observed: (i) an increase of DNA damage (from gel electrophoresis in DNA damage assay), (ii) an increase of recA expression (luminescence assay in recA - lux strain), and (iii) an increase of RecA protein level (Western blotting). When recA expression was repressed by novobiocin, or abolished by deleting the gene, S . aureus susceptibility towards photoinactivation was increased at approximately a hundred-fold. The absence of RecA increases DNA damage to yield bactericidal effect. In novobiocin-resistant mutant ( gyrB ), as opposed to wild type, neither RecA protein level nor cell’s susceptibility was affected by photoinactivation (when novobiocin is present). This is to suggest that GyrB-dependent inhibition mediated recA repression. Therefore, we have established the role of RecA in DNA damage during photoinactivation. With the use of rifampicin mutation frequency and Ames tests, we demonstrated that photoinactivation did not increase S . aureus mutagenesis and potentially is not mutagenic toward eukaryotic cells. The results suggest that the treatment is considered safe. In conclusion, we provide an evidence that recA inhibitor may serve as therapeutic adjuvant for antimicrobial photoinactivation. Clinical relevance of our findings warrants further investigations.

Description: The effect of a substitution site on orientation birefringence for cellulose triacetate (CTA) was investigated by the addition of xylan ester. Since CTA has three substitution sites (C-2, C-3, and C-6) while xylan ester has two substitution sites (C-2 and C-3), the change of birefringence by xylan acetate (XylAc) is attributed to the contribution of the C-6 acetyl group. Dynamic mechanical analysis and thermal measurements showed a single glass transition peak, indicating that XylAc is miscible with CTA at any compositions. The orientation birefringence (Δ n ) of CTA/XylAc films stretched beyond the glass transition temperature increased with increasing the XylAc content. The result for the stretched film suggested that the contribution of acetyl group in the C-2 and C-3 sites to Δ n is positive while that in the C-6 is negative. The negative sign for the C-6 site is in agreement with the result simulated by using the molecular dynamics method. In addition, Δ n of CTA films containing xylan propionate (or butyrate) indicated that the propionyl and butyryl groups in the C-2 and C-3 sites show positive birefringence similar to the acetyl group.

Description: In this study, the Ayvalik olive variety, an important and widely grown olive variety in Turkey, was chosen. A month prior to blooming and 2 months prior to harvesting in 2011 and 2012, three different concentrations of boron (100, 150 and 250 ppm) were applied to the olive leaves with or without boron deficiencies. After the application, quality criteria, fatty acid composition, total phenol contents and major volatile compounds of olive oil that was obtained from the harvested olives were investigated. Boron application to the olive trees with boron deficiencies has improved both the amount and the olive oil quality. Experimental results show the significance of boron for olive farming. Application of boron in 150 ppm led to a better olive oil quality by improving fatty acid composition [oleic acid (76.03 %), linoleic acid (9.68 %), linolenic acid (0.56 %), monounsaturated fatty acid (77.24 %)], total phenol content (422.94 ppm) and major volatile compounds [ E -2-hexenal (43.12 ppm), hexanal (3.02 ppm), Z -3-hexenol (1.13 ppm)] in both harvest seasons (2011–2012) and in both olive orchards with or without boron deficiencies.

Description: A simple setup using a 365-nm light-emitting diode coupled to a USB spectrometer through an optical fiber, in a front-face fluorescence configuration, was used to investigate the heat-induced deterioration of virgin olive oil at different heating temperatures and times. The samples were heated for 30, 60, 120 and 180 min for every temperature setting of 140, 160 and 180 °C, respectively. Two important results are reported in this article. First, a neo-formed compound around 665 nm due to the degradation of chlorophyll was observed. This new peak was attributed to pyropheophytins. The second result showed an important rise of the peak around 489 nm, which corresponded to the oxidation products. The correlation obtained between the peroxide value and the 489 nm peak using principal component analysis revealed the mechanism of the oxidation process. It further showed that the peak around 489 nm is a direct consequence of the degradation of hydroperoxide.

Description: Calcitonin participates in controlling homeostasis of calcium and phosphorus and plays an important role in bone metabolism. The aim of this study was to endow an industrial strain of Saccharomyces cerevisiae with the ability to express chimeric human/salmon calcitonin (hsCT) without the use of antibiotics. To do so, a homologous recombination plasmid pUC18- rDNA2 - ura 3- P pgk - 5hsCT - rDNA1 was constructed, which contains two segments of ribosomal DNA of 1.1 kb ( rDNA1 ) and 1.4 kb ( rDNA2 ), to integrate the heterologous gene into host rDNA. A DNA fragment containing five copies of a chimeric human/salmon calcitonin gene ( 5hsCT ) under the control of the promoter for phosphoglycerate kinase ( P pgk ) was constructed to express 5hsCT in S. cerevisiae using ura 3 as a selectable auxotrophic marker gene. After digestion by restriction endonuclease Hpa I, a linear fragment, rDNA2 - ura 3- P pgk - 5hsCT - rDNA1 , was obtained and transformed into the △ ura3 mutant of S. cerevisiae by the lithium acetate method. The ura 3- P pgk - 5hsCT sequence was introduced into the genome at rDNA sites by homologous recombination, and the recombinant strain YS- 5hsCT was obtained. Southern blot analysis revealed that the 5hsCT had been integrated successfully into the genome of S. cerevisiae . The results of Western blot and ELISA confirmed that the 5hsCT protein had been expressed in the recombinant strain YS- 5hsCT . The expression level reached 2.04 % of total proteins. S. cerevisiae YS- 5hsCT decreased serum calcium in mice by oral administration and even 0.01 g lyophilized S. cerevisiae YS- 5hsCT /kg decreased serum calcium by 0.498 mM. This work has produced a commercial yeast strain potentially useful for the treatment of osteoporosis.

Description: Since total petroleum hydrocarbons (TPH) are toxic and persistent in environments, studying the impact of oil contamination on microbial communities in different soils is vital to oil production engineering, effective soil management and pollution control. This study analyzed the impact of oil contamination on the structure, activity and function in carbon metabolism of microbial communities of Chernozem soil from Daqing oil field and Cinnamon soil from Huabei oil field through both culture-dependent techniques and a culture-independent technique—pyrosequencing. Results revealed that pristine microbial communities in these two soils presented disparate patterns, where Cinnamon soil showed higher abundance of alkane, (polycyclic aromatic hydrocarbons) PAHs and TPH degraders, number of cultivable microbes, bacterial richness, bacterial biodiversity, and stronger microbial activity and function in carbon metabolism than Chernozem soil. It suggested that complicated properties of microbes and soils resulted in the difference in soil microbial patterns. However, the changes of microbial communities caused by oil contamination were similar in respect of two dominant phenomena. Firstly, the microbial community structures were greatly changed, with higher abundance, higher bacterial biodiversity, occurrence of Candidate_division_BRC1 and TAO6 , disappearance of BD1-5 and Candidate_division_OD1 , dominance of Streptomyces , higher percentage of hydrocarbon-degrading groups, and lower percentage of nitrogen-transforming groups. Secondly, microbial activity and function in carbon metabolism were significantly enhanced. Based on the characteristics of microbial communities in the two soils, appropriate strategy for in situ bioremediation was provided for each oil field. This research underscored the usefulness of combination of culture-dependent techniques and next-generation sequencing techniques both to unravel the microbial patterns and understand the ecological impact of contamination.

Description: Hydrogen is a promising alternative as an energetic carrier and its production by dark fermentation from wastewater has been recently proposed, with special attention to crude glycerol as potential substrate. In this study, two different feeding strategies were evaluated for replacing the glucose substrate by glycerol substrate: a one-step strategy (glucose was replaced abruptly by glycerol) and a step-by-step strategy (progressive decrease of glucose concentration and increase of glycerol concentration from 0 to 5 g L −1 ), in a continuous stirred tank reactor (12 h of hydraulic retention time (HRT), pH 5.5, 35 °C). While the one-step strategy led to biomass washout and unsuccessful H 2 production, the step-by-step strategy was efficient for biomass adaptation, reaching acceptable hydrogen yields (0.4 ± 0.1 mol H2  mol −1 glycerol consumed ) around 33 % of the theoretical yield independently of the glycerol concentration. Microbial community structure was investigated by single-strand conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE) fingerprinting techniques, targeting either the total community (16S ribosomal RNA (rRNA) gene) or the functional Clostridium population involved in H 2 production (hydA gene), as well as by 454 pyrosequencing of the total community. Multivariate analysis of fingerprinting and pyrosequencing results revealed the influence of the feeding strategy on the bacterial community structure and suggested the progressive structural adaptation of the community to increasing glycerol concentrations, through the emergence and selection of specific species, highly correlated to environmental parameters. Particularly, this work highlighted an interesting shift of dominant community members (putatively responsible of hydrogen production in the continuous stirred tank reactor (CSTR)) according to the gradient of glycerol proportion in the feed, from the family Veillonellaceae to the genera Prevotella and Clostridium sp., putatively responsible of hydrogen production in the CSTR.

Description: Fucosyl- N -acetylglucosamine disaccharides are important core structures that form part of human mucosal and milk glyco-complexes. We have previously shown that AlfB and AlfC α-L-fucosidases from Lactobacillus casei are able to synthesize fucosyl-α-1,3-- N -acetylglucosamine (Fuc-α1,3-GlcNAc) and fucosyl-α-1,6- N -acetylglucosamine (Fuc-α1,6-GlcNAc), respectively, in transglycosylation reactions. Here, these reactions were performed in a semipreparative scale, and the produced disaccharides were purified. The maximum yields obtained of Fuc-α1,3-GlcNAc and Fuc-α1,6-GlcNAc were 4.2 and 9.3 g/l, respectively. The purified fucosyl-disaccharides were then analyzed for their prebiotic effect in vitro using strains from the Lactobacillus casei / paracasei / rhamnosus group and from Bifidobacterium species. The results revealed that 6 out of 11  L. casei strains and 2 out of 6  L. rhamnosus strains tested were able to ferment Fuc-α1,3-GlcNAc, and L. casei BL87 and L. rhamnosus BL327 strains were also able to ferment Fuc-α1,6-GlcNAc. DNA hybridization experiments suggested that the metabolism of Fuc-α1,3-GlcNAc in those strains relies in an α-L-fucosidase homologous to AlfB. Bifidobacterium breve and Bibidobacterium pseudocatenolatum species also metabolized Fuc-α1,3-GlcNAc. Notably, L-fucose was excreted from all the Lactobacillus and Bifidobacterium strains fermenting fucosyl-disaccharides, except from strains L. rhamnosus BL358 and BL377, indicating that in these latest strains, L-fucose was catabolized. The fucosyl-disaccharides were also tested for their inhibitory potential of pathogen adhesion to human colon adenocarcinoma epithelial (HT29) cell line. Enteropathogenic Escherichia coli (EPEC) strains isolated from infantile gastroenteritis were used, and the results showed that both fucosyl-disaccharides inhibited adhesion to different extents of certain EPEC strains to HT29 cells in tissue culture.

Description: Gluconacetobacter xylinus (formerly Acetobacter xylinum and presently Komagataeibacter medellinensis ) is known to produce cellulose as a stable pellicle. However, it is also well known to lose this ability very easily. We investigated the on and off mechanisms of cellulose producibility in two independent cellulose-producing strains, R1 and R2. Both these strains were isolated through a repetitive static culture of a non-cellulose-producing K. medellinensis NBRC 3288 parental strain. Two cellulose synthase operons, types I and II, of this strain are truncated by the frameshift mutation in the bcsBI gene and transposon insertion in the bcsCII gene, respectively. The draft genome sequencing of R1 and R2 strains revealed that in both strains the bcsBI gene was restored by deletion of a nucleotide in its C-rich region. This result suggests that the mutations in the bcsBI gene are responsible for the on and off mechanism of cellulose producibility. When we looked at the genomic DNA sequences of other Komagataeibacter species, several non-cellulose-producing strains were found to contain similar defects in the type I and/or type II cellulose synthase operons. Furthermore, the phylogenetic relationship among cellulose synthase genes conserved in other bacterial species was analyzed. We observed that the cellulose genes in the Komagataeibacter shared sequence similarities with the γ-proteobacterial species but not with the α-proteobacteria and that the type I and type II operons could be diverged from a same ancestor in Komagataeibacter .

Description: Currently, contamination of indoor environment by fungi and molds is considered as a public health problem. The monitoring of indoor airborne fungal contamination is a common tool to help understanding the link between fungi in houses and respiratory problems. Classical analytical monitoring methods, based on cultivation and microscopic identification, depend on the growth of the fungi. Consequently, they are biased by difficulties to grow some species on certain culture media and under certain conditions or by noncultivable or dead fungi that can consequently not be identified. However, they could have an impact on human health as they might be allergenic. Since molecular methods do not require a culture step, they seem an excellent alternative for the monitoring of indoor fungal contaminations. As a case study, we developed a SYBR® green real-time PCR-based assay for the specific detection and identification of Aspergillus versicolor , which is frequently observed in indoor environment and known to be allergenic. The developed primers amplify a short region of the internal transcribed spacer 1 from the 18S ribosomal DNA complex. Subsequently, the performance of this quantitative polymerase chain reaction (qPCR) method was assessed using specific criteria, including an evaluation of the selectivity, PCR efficiency, dynamic range, and repeatability. The limit of detection was determined to be 1 or 2 copies of genomic DNA of A. versicolor . In order to demonstrate that this SYBR® green qPCR assay is a valuable alternative for monitoring indoor fungal contamination with A. versicolor , environmental samples collected in contaminated houses were analyzed and the results were compared to the ones obtained with the traditional methods.

Description: Fiber mat materials based on cellulose natural fibers combines a useful set of properties, including renewability, stiffness, strength and dielectric insulation, etc. The dominant in-plane fiber orientation ensures the in-plane performance, at the expense of reduced out-of-plane behavior, which has not been studied as extensively as the in-plane behavior. Quantitative use of X-ray micro-computed tomography and strain analyses under in-situ loading open up possibilities to identify key mechanisms responsible for deformation. In the present investigation, focus is placed on the out-of-plane deformation under compressive loading of thick, high density paper, known as pressboard. The samples were compressed in the chamber of a microtomographic scanner. 3D images were captured before and after the loading the sample. From sequential 3D images, the strain field inside the material was calculated using digital volume correlation. Two different test pieces were tested, namely unpolished and surface polished ones. The first principal strain component of the strain tensor showed a significant correlation with the density variation in the material, in particular on the top and bottom surfaces of unpolished samples. The manufacturing-induced grooves generate inhomogeneities in the microstructure of the surface, thus creating high strain concentration zones which give a sensible contribution to the overall compliance of the unpolished material. More generally, the results reveal that, on the micrometer scale, high density fiber pressboard behaves as a porous material rather than a low density fiber network.

Description: Ti 3+ -doped TiO 2 nanosheets with tunable phase composition (doped TiO 2 (A/R)) were synthesized via a hydrothermal method with high surface area anatase TiO 2 nanosheets TiO 2 (A) as a substrate, structure directing agent, and inhibitor; the activity was evaluated using a probe reaction-photocatalytic CO 2 conversion to methane under visible light irradiation with H 2 as an electron donor and hydrogen source. High-resolution transmission electron microscope (HRTEM), field emission scanning electron microscope, UV-Vis diffuse reflectance spectra, and X-ray diffraction (XRD) etc., were used to characterize the photocatalysts. XRD and HRTEM measurements confirmed the existence of anatase-rutile phase junction, while Ti 3+ and single-electron-trapped oxygen vacancy in the doped TiO 2 (A/R) photocatalyst were revealed byelectron paramagnetic resonance (EPR) measurements. Effects of hydrothermal synthesis temperature and the amount of added anatase TiO 2 on the photocatalytic activity were elucidated. Significantly enhanced photocatalytic activity of doped TiO 2 (A/R) was observed; under the optimized synthesis conditions, CH 4 generation rate of doped TiO 2 (A/R) was 2.3 times that of Ti 3+ -doped rutile TiO 2 .

Description: Butanol is a promising biofuel with high energy intensity and can be used as gasoline substitute. It can be produced as a sustainable energy by microorganisms (such as Clostridia) from low-value biomass. However, the low productivity, yield and selectivity in butanol fermentation are still big challenges due to the lack of an efficient butanol-producing host strain. In this article, we systematically review the host cell engineering of Clostridia, focusing on (1) various strategies to rebalance metabolic flux to achieve a high butanol production by regulating the metabolism of carbon, redox or energy, (2) the challenges in pathway manipulation, and (3) the application of proteomics technology to understand the intracellular metabolism. In addition, the process engineering is also briefly described. The objective of this review is to summarize the previous research achievements in the metabolic engineering of Clostridium and provide guidance for future novel strain construction to effectively produce butanol.

Description: Mechanical stress caused by agitation is one of the factors that can affect hematopoietic stem cell expansion in suspension bioreactors. Therefore, we have investigated the effects of agitation on umbilical cord blood hematopoietic stem cell (UCB-HSC) growth and differentiation. A comparison was made between various agitation rates (20, 40 and 60 rpm) in spinner-flask and cells cultured in glass petri dish as a static culture. Moreover, the fluid dynamic at various agitation rates of spinner-flask was analyzed to determine shear stress. The spinner-flask contained a rotational moving mixer with glass ball and was kept in tissue culture incubator. To reduce consumption of cytokines, UCB-serum was used which widely decreased the costs. Our results determined that, agitation rate at 40 rpm promoted UCB-HSCs expansion and their colony forming potential. Myeloid progenitors were the main type of cells at 40 rpm agitation rate. The results of glucose consumption and lactic acid production were in complete agreement with colony assay and expansion data and indicated the superiority of culture in spinner-flask when agitated at 40 rpm over to other agitation speeds and also static culture. Cell viability and colony count was affected by changing the agitation speed. We assume that changes in cell growth resulted from the effect of shear stress directly on cell viability, and indirectly on signaling pathways that influence the cells to differentiate.

Description: Alphaproteobacterium strain Q-1 produces an extracellular multicopper oxidase (IOX), which catalyzes iodide (I – ) oxidation to form molecular iodine (I 2 ). In this study, the antimicrobial activity of the IOX/iodide system was determined. Both Gram-positive and Gram-negative bacteria tested were killed completely within 5 min by 50 mU mL –1 of IOX and 10 mM iodide. The sporicidal activity of the system was also tested and compared with a common iodophor, povidone-iodine (PVP-I). IOX (300 mU mL –1 ) killed Bacillus cereus , B. subtilis , and Geobacillus stearothermophilus spores with decimal reduction times of 2.58, 7.62, and 40.9 min, respectively. However, 0.1 % PVP-I killed these spores with much longer decimal reduction times of 5.46, 38.0, and 260 min, respectively. To evaluate the more superior sporicidal activity of the IOX system over PVP-I, the amount of free iodine (non-complexed I 2 ) was determined by an equilibrium dialysis technique. The IOX system included more than 40 mg L –1 of free iodine, while PVP-I included at most 25 mg L –1 free iodine. Our results suggest that the new enzyme-based antimicrobial system is effective against a wide variety of microorganisms and bacterial spores, and that its strong biocidal activity is due to its high free iodine content, which is probably maintained by re-oxidation of iodide released after oxidation of cell components by I 2 .