ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (63)
  • immobilization  (38)
  • Yeast  (25)
  • Springer  (63)
  • American Association for the Advancement of Science (AAAS)
  • American Institute of Physics (AIP)
  • Process Engineering, Biotechnology, Nutrition Technology  (63)
Collection
  • Articles  (63)
Publisher
  • Springer  (63)
  • American Association for the Advancement of Science (AAAS)
  • American Institute of Physics (AIP)
  • Wiley-Blackwell  (61)
  • Elsevier  (13)
Years
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 151-154 
    ISSN: 1573-0972
    Keywords: Invertases ; immobilization ; phenyl-Sepharose ; thermophilic fungus ; yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An invertase from the thermophilic fungus, Thermomyces lanuginosus was immobilized on phenyl-Sepharose and its properties were studied. Between the soluble and immobilized forms of the invertase, there were not much difference in their optimum pH, K M and V max for sucrose. In contrast, the K M and V max for raffinose changed significantly. The optimum temperature for the immobilized invertase was lower by 10 ∘C. The immobilized invertase showed remarkable stability at 50 ∘C and was less sensitive to inhibition by metal ions. There was no leaching of the enzyme for at least a month when stored in the refrigerator. The method is novel and specific for the thermophilic invertase as a mesophilic invertase (from yeast) did not bind to phenyl-Sepharose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 245-248 
    ISSN: 1573-0972
    Keywords: Acetobacter xylinum ; biotechnology ; carbon source ; cellulose membrane ; immobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effect of various carbon and nitrogen sources on cellulose membrane production by Acetobacter xylinum was evaluated. Among the carbon sources, sucrose, glucose and mannitol were found to be suitable for optimum levels of cellulose production. The strain was able to utilize a wide range of protein and nitrogen sources such as peptone, soybean meal, glycine, casein hydrolysate, and glutamic acid for cellulose synthesis. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of pellicle proteins (PP) revealed electrophoretic bands of molecular masses in the range of 116–20 kDa. Furthermore, the strain can be useful for the removal of various nitrogenous and carbon substrates present in waste waters.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 15 (1999), S. 465-469 
    ISSN: 1573-0972
    Keywords: Biotransformation ; codeine ; immobilization ; morphine ; Spirulina platensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Both freely suspended cells and immobilized cultures of Spirulina platensis, a blue-green alga, biotransformed exogenously fed codeine, an opium alkaloid, to morphine. The external addition of codeine to the culture medium did not affect the growth of S. platensis. Immobilization of Spirulina in a calcium alginate gel matrix was optimized by using 2% (w/v) sodium alginate and reducing the concentration of nutrients of Zarrouk's medium, which caused destabilization of the calcium alginate gel. The accumulation of morphine increased gradually and reached maxima of 330 μg 100 ml−1 culture at 105 h in freely suspended and 351 μg 100 ml−1 at 96 h in immobilized Spirulina cultures. Accumulation of morphine was detected only in the medium, whereas cells did not show accumulation. The immobilized Spirulina cultures showed marginally higher conversion of codeine to morphine over freely suspended cultures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 15 (1999), S. 515-516 
    ISSN: 1573-0972
    Keywords: Biofilter ; biodegradation ; effluent ; fertilizer ; immobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A biofilter composed of yeasts and cassava peel was used to detoxify fertilizer plant effluent. The biological oxygen demand was reduced on treatment from a range of 1200–1400 mg/l to a range 135–404 mg/l. The ammonia-nitrogen (NH3–N) and nitrate-nitrogen (NO3–N) were reduced after treatment from 1000 to 10 mg/l and from 100 to 17.6 mg/l, respectively. The biofilter is simple and easy to handle with high efficiency of 98%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-0972
    Keywords: Adhesion ; cotton threads ; immobilization ; invert sugar ; microbial filter ; polyethylenimine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Polyethylenimine(PEI)-coated cotton threads were shown to have potential for reducing microbial load from a flowing suspension. Turbid cell suspensions perfused through the PEI column appeared as totally clear in the effluent. The adhesion efficiency of the matrix was found to depend on the concentration of PEI used to treat the threads. Threads coated with 2.5% PEI were found to show optimal retention of cells. A considerable amount of binding was seen over a broad range of ionic concentration (0–0.3 M) and pH (3.6–10.3). Under similar conditions control threads did not show any filtration capacity. Saccharomyces cerevisiae, Saccharomyces fragilis, Escherichia coli and an Acetobacter species could be effectively filtered using PEI-coated threads. This technique can find potential for the simultaneous filtration and immobilization of cells in a bioreactor to be used in continuous bioprocessing as exemplified for the inversion of sucrose syrups using baker's yeast. The bioreactor could continuously hydrolyse 60% (w/v) sucrose syrups with a productivity of 2.25 kg/day for over a month without loss in efficiency.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 15 (1999), S. 57-63 
    ISSN: 1573-0972
    Keywords: Yeast ; high pressure homogenization ; papain ; autolysis ; yeast extract ; clarification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effect of high pressure homogenization (600 and 1000 bar) prior to autolysis of a commercial pressed baker's yeast was examined. High pressure homogenization released a maximum of 30% of the solids and 34% of the total nitrogen (TN). After autolysis of the whole homogenized slurry, high yields of solids and TN (up to 81 and 85%, respectively) were obtained. Autolysis of non-homogenized controls yielded much lower yield values (30 and 39%, respectively), whereas autolysis in the presence of papain but without prior disruption gave intermediate values (50 and 61%, respectively). The various treatments led to changes in the extract composition: standard autolysates had the highest total nitrogen and true protein weight contents and the lowest carbohydrate content, whereas this trend was reversed when cells were first disrupted before autolysis. In contrast to controls obtained by standard autolysis without or with papain, centrifuged autolysates from pre-homogenized fractions were not clear. Treatment with a combination of a flocculation and a weighting agent clarified the extracts but resulted in a loss of solids (approximately 20%), including nitrogen and carbohydrates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-0972
    Keywords: Yeast ; ethanol ; alcohol ; thermotolerant ; thermophilic ; Kluyveromyces marxianus IMB3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract It is clear that only a small proportion of all micro-organisms have been isolated and identified. The simple technique of seeking a thermotolerant fermentative yeast from a suitable hot environment has yielded a number of strains. These organisms, identified as strains of Kluyveromyces marxianus var. marxianus, have been shown to have a wide range of metabolic capabilities that could be used in industrial applications. Not only have the metabolic capabilities been elucidated but possible bioreactor configurations and process application options have been investigated. It appears that there are a number of specific situations where this thermotolerant yeast could find industrial applications. A full-scale industrial ethanol production trial using this yeast was successfully carried out in India. K. marxianus IMB3's performance in terms of the ethanol concentrations achieved was comparable to that obtained using the distillery's own yeast strain with an added advantage of eliminating cooling.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-0778
    Keywords: concanavalin A ; cytotoxic T lymphocytes ; immobilization ; interleukin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Human tumor-specific CD4+ cytotoxic T lymphocytes (CTL) were generated against duodenum papilloma cell line TGBC18TKB from HLA type-matched peripheral blood mononuclear cells. Concanavalin A (Con A) immobilized on carrier beads stimulated growth of the CTL in a long-term culture without repeated antigen stimulation, while soluble Con A induced death of the CTL. The CTL exhibited the target-specific cytotoxicity in a more potent manner than those before the long-term culture in the presence of the immobilized Con A. Enhanced expression of the adhesion molecule, CD11b, was observed on the CTL. These results suggest that immobilized Con A will be useful for continuous growth stimulation and large scale expansion of CTL without tumor antigen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 14 (1998), S. 447-450 
    ISSN: 1573-0972
    Keywords: Claviceps ; ergot alkaloids ; immobilization ; surfactant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In a semicontinuous process immobilized Claviceps paspali mycelia produced alkaloids over a period of 60 days (six reincubations). By addition of the surfactant Pluronik, a polyethoxypolypropoxy polymer, a considerable increase in alkaloid biosynthesis occurred. The maximum product concentration achieved was 8.35gl-1, and the overall productivity was 5.80 mgl-1 h-1, which is half the productivity of the batch process. Maximum process productivity for a single reincubation (12.3 mg l-1 h-1) was almost equal to the batch process productivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 14 (1998), S. 927-929 
    ISSN: 1573-0972
    Keywords: Urease ; pigeonpea ; Cajanus cajan ; immobilization ; urea analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Urease of pigeonpea has been immobilized on polyethyleneimine-activated cotton cloth followed by cross-linking with dimethyl suberimidate. Optimum immobilization (56%) was obtained at a protein loading of 1.2mg/5×5cm2 cloth piece. The immobilized enzyme stored in 0.1M Tris/acetate buffer, pH6.5, at 4°C had a t1/2 of 70 days. There was practically no leaching of the enzyme from the immobilization matrix in 15 days. The immobilized enzyme was used 7 times at an interval of 24h between each use with 75% residual activity at the end of the period. Blood urea analysis was carried out with immobilized urease for some clinical samples.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 14 (1998), S. 343-348 
    ISSN: 1573-0972
    Keywords: Biofilter ; immobilization ; malodour ; volatile fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract n-Valeric acid, one of the main malodorous pollutants from livestock houses was eliminated with a biofilter prepared with Rhodococcus sp. B261 immobilized onto ceramic beads. The strain was isolated from composted pig faeces and grown in an artificial medium containing volatile fatty acids as a carbon source. The cells were immobilized onto ceramic beads in vacuo. The beads were aseptically incubated at 37 °C, pH 8.0, for 24h for activation of the cells. The beads with immobilized cells (3.36×109 c.f.u./g ceramic beads) and moisture content of 35% (w/w) were packed into a glass column equipped with a water jacket to keep the temperature constant. One hundred-seventy ppm of gaseous n-valeric acid were removed for 11 days at 30h -1 (space velocity) and 37 °C.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1573-0778
    Keywords: fixed bed reactor ; immobilization ; dialysis technique ; hybridoma cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An industrial scale reactor concept for continuous cultivation of immobilized animal cells (e.g. hybridoma cells) in a radial-flow fixed bed is presented, where low molecular weight metabolites are removed via dialysis membrane and high molecular products (e.g. monoclonal antibodies) are enriched. In a new “nutrient-split” feeding strategy concentrated medium is fed directly to the fixed bed unit, whereas a buffer solution is used as dialysis fluid. This feeding strategy was investigated in a laboratory scale reactor with hybridoma cells for production of monoclonal antibodies. A steady state monoclonal antibody concentration of 478 mg l-1 was reached, appr. 15 times more compared to the concentration reached in chemostat cultures with suspended cells. Glucose and glutamine were used up to 98%. The experiments were described successfully with a kinetic model for immobilized growing cells. Conclusions were drawn for scale-up and design of the large scale system. Abbreviations: cGlc – glucose concentration, mmol l-1; cGln – glutamine concentration, mmol l-1; cAmm – ammonia concentration, mmol l-1; cLac – lactate concentration, mmol l-1; cMAb – MAb concentration, mg l-1; D – dilution rate, d-1; Di – dilution rate in the inner chamber of the membrane dialysis reactor, d-1; D0 – dilution rate in the outer chamber of the membrane dialysis reactor, d-1; q*FB,Glc – volume specific glucose uptake rate related to the fixed bed volume, mmol lFB -1 h-1; q*FB,Gln – volume specific glutamine uptake rate related to the fixed bed volume, mmol lFB -1 h-1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1573-0778
    Keywords: monoclonal antibody ; immobilization ; collagen gel ; BHK ; productivity ; recombinant ; high density culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Animal cell perfusion high density culture is often adopted for the production of biologicals in industry. In high density culture sometimes the productivity of biologicals has been found to be enhanced. Especially in immobilized animal cell culture, significant increase in the productivity has been reported. We have found that the specific monoclonal antibody (MAb) productivity of an immobilized hybridoma cell is enhanced more than double. Several examples of enhancing productivities have been also shown by collagen immobilized cells. Immobilized cells involve some different points from non-immobilized cells in high density culture: In immobilized culture, some cells are contacted together, resulting in locally much higher cell concentration more than 108 cells/ml. Information originating from a cell can be easily transduced to the others in immobilized culture because the distance between cells is much nearer. Here we have performed collagen gel immobilized culture of recombinant BHK cells which produce a human IgG monoclonal antibody in a protein-free medium for more than three months. In this high density culture a stabilized monoclonal antibody production was found with around 8 times higher specific monoclonal antibody productivity compared with that in a batch serum containing culture. No higher MAb productivity was observed using a conditioned medium which was obtained from the high density culture, indicating that no components secreted from the immobilized cells work for enhancing monoclonal antibody production. The MAb productivity by the non-immobilized cells obtained by dissolving collagen using a collagenase gradually decreased and returned to the original level in the batch culture using a fresh medium. This suggests that the direct contact of the cells or a very close distance between the cells has something to do with the enhancement of the MAb productivity, and the higher productivity is kept for a while in each cell after they are drawn apart.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1573-0972
    Keywords: Biodegradation ; immobilization ; laccase ; olive oil mill wastewater ; white rot fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The biodegradation of olive oil mill wastewater (OOMW) by Coriolus versicolor and Funalia trogii was investigated. Initial COD concentration, agitation and inoculum size were all found to be significant for biodegradation. Adding glucose, sulphate or nitrogen had no effect on biodegradation. During growth in optimum conditions, C.versicolor removed approximately 63% COD, 90% phenol and 65% colour within 6 days and F. trogii removed approximately 70% COD, 93% phenol and 81% colour of the OOMW used. The fungi also excreted large amounts of extracellular laccase into the medium. High biodegradation yields were also obtained by fungi immobilized in calcium alginate gels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 14 (1997), S. 107-111 
    ISSN: 1573-0972
    Keywords: Glutaraldehyde ; immobilization ; monochloroacetic acid ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 13 (1997), S. 597-598 
    ISSN: 1573-0972
    Keywords: Glucose isomerase ; immobilization ; production ; purification ; Streptomyces olivochromogenes PTCC 1457
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Production of glucose isomerase from Streptomyces olivochromogenes PTCC 1457 was followed by its purification and immobilization. Different immobilization methods including the use of a hydrophobic support were investigated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 14 (1997), S. 247-250 
    ISSN: 1573-0972
    Keywords: Baker's yeast ; 18-crown-6 ; imines ; immobilization ; oximes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Immobilized baker's yeast entrapped in calcium alginate beads efficiently reduces N-benzylidinemethylamine to N-methylbenzylamine in hexane at 37°C and tetrahydrofuran (THF) at 30°C in the presence of 18-crown-6, while in the presence of water as cosolvent and glucose as an additive N-benzylidinemethylamine undergoes decomposition. Benzaldoxime in a hexane–water (1:9) solvent system containing glucose as an additive is reduced to N-benzylhydroxylamine. On using an ethanol–water (1:1) solvent system, benzaldoxime is converted to benzyl alcohol and in hexane, benzene, THF, hexane–water (1:1) or acetonitrile–water (1:1) solvent systems, or using dried baker's yeast in different solvent systems, transformation of benzaldoxime does not occur.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 13 (1997), S. 469-473 
    ISSN: 1573-0972
    Keywords: 2-Deoxy-d-glucose ; hydroxylation ; immobilization ; polyoxin ; protoplasts ; steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 79-101 
    ISSN: 1476-5535
    Keywords: alginate ; bacteria ; biodegradation ; bioremediation ; κ-carrageenan ; encapsulation ; immobilization ; microorganisms ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Immobilized microbial cells have been used extensively in various industrial and scientific endeavours. However, immobilized cells have not been used widely for environmental applications. This review examines many of the scientific and technical aspects involved in using immobilized microbial cells in environmental applications, with a particular focus on cells encapsulated in biopolymer gels. Some advantages and limitations of using immobilized cells in bioreactor studies are also discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 351-353 
    ISSN: 1476-5535
    Keywords: citric acid ; Aspergillus niger ; immobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Aspergillus niger was immobilized in cryogels and in conventional gels of polyacrylamide. The growth of cells entrapped in two kinds of gels and the production of citric acid by the immobilized cells were investigated and compared. Cells immobilized in cryogels were more suitable for citric acid production.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 17 (1996), S. 15-19 
    ISSN: 1476-5535
    Keywords: glucose oxidase ; catalase ; Penicillium variabile ; immobilization ; polyurethane sponge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Conidia ofPenicillium variabile P16 were immobilized in polyurethane sponge and used in repeated-batch processes in a fluidized-bed reactor. Optimal conditions for production of glucose oxidase and catalase were: inoculum size, 10%; glucose concentration, 80 g L−1; Ca-carbonate concentration, 15 g L−1; temperature, 28°C and aeration rate, 4 VV−1 min−1. In an extended repeated-batch process, glucose oxidase activity was highest after the fourth batch and catalase activity was highest after the fifth batch. Scanning electron microscopy showed that the fungus grew only in the interior of carrier particles.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 17 (1996), S. 11-14 
    ISSN: 1476-5535
    Keywords: continuous flow reactor ; ethanol ; expanded bed reactor ; immobilization ; Zymomonas mobilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Continuous ethanol fermentation by immobilized whole cells ofZymomonas mobilis was investigated in an expanded bed bioreactor and in a continuous stirred tank reactor at glucose concentrations of 100, 150 and 200 g L−1. The effect of different dilution rates on ethanol production by immobilized whole cells ofZymomonas mobilis was studied in both reactors. The maximum ethanol productivity attained was 21 g L−1 h−1 at a dilution rate of 0.36 h−1 with 150 g glucose L−1 in the continuous expanded bed bioreactor. The conversion of glucose to ethanol was independent of the glucose concentration in both reactors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1573-0972
    Keywords: Alginate ; cellulase ; cellulose ; ethanol ; immobilization ; Kluyveromyces marxianus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The thermotolerant yeast, Kluyveromyces marxianus IMB3, was grown in batch culture at 45°C on cellulose-containing media, supplemented with exogenous cellulase activity. At various stages during fermentation, both substrate and enzyme were added in batch mode and fermentation was continued for 220 h. Ethanol production increased to 20 g/l at 200 h, representing 45% of the maximum theoretical yield. In subsequent experiments, the organism was immobilized in calcium alginate beads and these were used in a similar, batch-fed system at 45°C. Again, fermentation was continued for 220 h and ethanol production increased to its maximum, of 28 g/l, within 100 h and this represented in excess of 60% of the maximum theoretical yield.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 12 (1996), S. 25-27 
    ISSN: 1573-0972
    Keywords: Batch fermentation ; immobilization ; Saccharomyces cerevisiae ; secondary products ; wine yeast ; wine making
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Five, highly flocculeng strains of Saccharomyces cerevisiae, isolated from wine, were immobilized in calcium alginate beads to optimize primary must fermentation. Three cell-recycle batch fermentations (CRBF) of grape musts were performed with the biocatalyst and the results compared with those obtained with free cells. During the CRBF process, the entrapped strains showed some variability in the formation of secondary products of fermentation, particularly acetic acid and acetaldehyde. Recycling beads of immobilized flocculent cells is a good approach in the development and application of the CRBF system in the wine industry.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 164-168 
    ISSN: 1476-5535
    Keywords: Nickel ; Resistance ; Yeast ; Fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary This review describes nickel toxicity and nickel resistance mechanisms in fungi. Nickel toxicity in fungi is influenced by environmental factors such as pH, temperature and the existence of organic matter and other ions. We describe resistance mechanisms in nickel-resistant mutants of yeasts and filamentous fungi which were obtained by exposure to a mutagen or by successive culture in media containing increasing concentrations of nickel ion. Nickel resistance may involve: (1) inactivation of nickel toxicity by the production of extracellular nickel-chelating substances such as glutathione; (2) reduced nickel accumulation, probably by modification of a magnesium transport system; (3) sequestration of nickel into a vacuole associated with free histidine and involving Ni-insensitivity of vacuolar membrane H+-ATPase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 240-246 
    ISSN: 1476-5535
    Keywords: Yeast ; Copper ; Silver ; Ion selective electrodes ; Metal complexation ; Metal uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Three strains ofSaccharomyces cerevisiae and one strain of aCandida sp. obtained from different industrial sources were screened for uptake of silver and copper. Considerable differences in metal uptake capacities were found between the different strains ofS. cerevisiae and betweenS. cerevisiae and theCandida sp. used. Copper uptake capacities ranged from 0.05 mmol g−1 dry wt to 0.184 mmol g−1 dry wt while values of 0.034 mmol Ag g−1 dry wt and 0.193 mmol Ag g−1 dry wt biomass were observed. Use of ion-selective electrodes (ISEs) enabled the detection of copper complexing agents (possibly proteins and carbohydrates) released by yeasts into the surrounding medium. In contrast, these compounds had no silver complexation abilities. Langmuir and Scatchard transformations of metal adsorption isotherms suggested differences in the mechanisms involved in metal uptake by the various yeasts. The differences between strains ofS. cerevisiae were due possibly to differences in cell wal composition. Different methods of preparation of biomass (fresh, air, oven and freeze-dried) had little effect on metal uptake in comparison with fresh biomass. Storage of fresh waste biomass at 4°C for 20 days had no effect on metal biosorption capacities. It was also observed that individual batches of waste biomass produced from different fermentation runs had consistent metal uptake capacities. The implications of the above results on the use of waste yeast biomass for treatment of metal-containing effluents are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 502-507 
    ISSN: 1476-5535
    Keywords: Phaffia rhodozyma ; Astaxanthin ; Carotenoids ; Yeast ; Singlet oxygen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The only known habitat of the astaxanthin-containingPhaffia rhodozyma is in slime fluxes of deciduous trees at high altitudes. In this habitat, the function of carotenoids inP. rhodozyma is probably to provide protection against photogenerated antifungal substances in the tree flux such as singlet oxygen (1O2). To investigate the role of carotenoids inP. rhodozyma, genetic selections were employed to determine if carotenogenic yeast strains ofP. rhodozyma have enhanced ability to quench1O2. Singlet oxygen was generated in liquid culture by the interaction of visible light (λ-550 nm) with the photosensitizer rose bengal or by the activation of α-terthienyl with ultraviolet light (λ=366 nm). In each case the treatments selected for growth of pigmented strains ofP. rhodozyma. Albino (carotenoid-less) or yellow (β-carotene producing) strains grew less well in media containing1O2. Addition of the1O2 quencher sodium azide to the medium with α-terthienyl allowed growth of non-pigmented strains. Since the ecological niche ofP. rhodozyma is highly specific, we investigated whether extracts of birch trees (Betula), the original source ofP. rhodozyma, contained a compound that would select for pigmented populations of the yeast. WhenP. rhodozyma strains were exposed to ethyl acetate extracts ofBetula papyrifera excited with 366 nm ultraviolet light, only pigmented cells were able to grow. These results suggest that carotenogenesis developed inP. rhodozyma in response to the presence of photoactivatable antifungal compounds produced by the host tree.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1476-5535
    Keywords: Yeast ; Oleaginous ; Rhodotorula glutinis ; Lipid ; Fat ; Molasses ; Fed batch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Rhodotorula glutinis is known to produce fat when cultivated under nitrogen-limiting conditions. Economically, molasses is an ideal substrate, however, due to the presence of nitrogen in molasses, the lipid yield obtained is much lower than that obtained from glucose or sucrose. Higher yields were obtained using molasses in a fed batch fermentation supplemented with glucose or sucrose during the lipid accumulation phase. The fatty acids profile of the lipids thus produced, using a very simple and economical medium, was similar to that obtained from glucose and sucrose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 355-364 
    ISSN: 1476-5535
    Keywords: Transformation ; Fungi ; Yeast ; Genetics ; Biotechnology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The genetic investigation of fungi has been extended substantially by DNA-mediated transformation, providing a supplement to more conventional genetic approaches based upon sexual and parasexual processes. Initial transformation studies with the yeastSaccharomyces cerevisiae provided the model for transformation systems in other fungi with regard to methodology, vector construction and selection strategies. There are, however, certain differences betweenS. cerevisiae and filamentous fungi with regard to type of genomic insertion and the availability of shuttle vectors. Single-site linked insertions are common in yeast due to the high level of homology required for recombination between vectored and genomic sequences, whereas mycelial fungi often show a high frequency of heterologous and unlinked insertions, often in the form of random and multiple-site integrations. While extrachromosomally-maintained or replicative vectors are readily available for use with yeasts, such vectors have been difficult to construct for use with filamentous fungi. The development of vectors for replicative transformation with these fungi awaits further study. It is proposed that replicative vectors may be inherently less efficient for use with mycelial fungi relative to yeasts, since the mycelium, as an extended and semicontinuous network of cells, may delimit an adequate diffusion of the vector carrying the selectable gene, thus leading to a high frequency of abortive or unstable transformants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 389-395 
    ISSN: 1476-5535
    Keywords: Astaxanthin ; Yeast ; Pigment ; Corn wet-milling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Natural isolates of the carotenoid-producing yeastPhaffia rhodozyma were analyzed for their ability to grow and to produce carotenoids in culture media composed exclusively of co-products of corn wet-milling for fuel ethanol production. FiveP. rhodozyma strains were tested for biomass produced (dry weight) and carotenoid yield. Six co-products were examined, ranging in cost from approximately $0.02 per kg to $0.11 per kg, all less expensive than conventional or agricultural growth substrates previously tested. The three co-products allowing the greatest accumulation of biomass and carotenoids byP. rhodozyma were thin stillage (TS), corn condensed distiller's solubles (CCDS) and corn gluten feed (CGF). Of the medium compositions tested, 10–15% CGF, 70% TS and 6–8% CCDS generally allowed maximum carotenoid production. Cultures grown in these three media produced up to 65%. 148% and 104% of the carotenoid yield per ml of yeast extract/malt extract (YM) cultures, respectively. Under the conditions tested, this was at an approximate medium cost of $0.67 per g carotenoids for CCDS and $0.73 per g for CGF as compared to $385.00 per g for YM. These results indicate that certain co-products of corn wet-milling can serve, at the appropriate concentration, as efficient, economical substrates for growth and carotenoid production byPhaffia rhodozyma.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 11 (1995), S. 156-159 
    ISSN: 1573-0972
    Keywords: Bacillus ; biogas-H ; hydrogen ; immobilization ; mixed culture ; recycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Viable cells of H2-producers (Bacillus licheniformis and a mixed microbial culture) were immobilized on brick dust and in calcium alginate beads. In batch culture, cells of the mixed culture in the free state yielded 8.2 l H2/mol glucose utilized, whereasB. licheniformis evolved 13.1 l H2. Immobilized cells, however, gave 4-fold more H2 than the free bacteria. Highest yields were from the cells immobilized on brick dust. High H2-production rates continued over two rounds of re-use of the immobilized cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 13 (1994), S. 17-23 
    ISSN: 1476-5535
    Keywords: Yeast ; Glycerol production ; Low alcohol content wine ; Enology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Mutants partially resistant to the repressive effect of glucose have been isolated from aSaccharomyces cerevisiae strain totally deficient in phosphoglycerate mutase activity (EC 5.4.2.1) by a selection procedure involving the catabolite-repressive effect of 5-thio-d-glucose (5TG). These mutants are able to resist glucose concentrations up to 15 g L−1 and exhibit several non-repressed metabolic pathways such as gluconeogenesis, glyoxylic shunt or mitochondrial respiratory chain. Moreover, when these mutants are grown in aerobiosis on ethanol and glucose as sole substrates, glucose is mainly converted into glycerol in order to maintain a normal redox balance. Optimal glucose and oxygen concentrations have been defined for resting cells in order to obtain a glycerol yield from glucose close to 100%. The physiological characteristics of one of these mutants led us to consider an application of this yeast strain in reducing the ethanol content of wines previously lowered in ethanol content by physical processes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 13 (1994), S. 172-176 
    ISSN: 1476-5535
    Keywords: Immobilization ; Hydrophobic ; Hydrophilic ; Polymers ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Biotransformation of benzaldehyde to benzyl alcohol bySaccharomyces cerevisiae immobilized in different support matrices was investigated. Polymers with intrinsic hydrophobic and/or hydrophilic nature as well as mixed hydrophobic and hydrophilic supports were examined both in aqueous and bisphasic aqueous-organic systems. The hydrophobic support material ENTP-2000 or mixed silicone:alginate (50-25∶50-75) proved to be most suitable not only for nonconventional media but also for conventional aqueous media for production of benzyl alcohol. With ENTP-2000, catalytic activity and maximum yield were 159 μmol h−1 g−1 dry weight catalyst and 0.89 mM, respectively, in hexane containing 2% moisture. Corresponding values in aqueous media were 246 μmol h−1 g−1 dry weight catalyst and 1.53 mM. With 50∶50 silicone:alginate, catalytic activity and maximum yield were 177 μmol h−1 g−1 dry weight catalyst and 1.18 mM, respectively, in hexane containing 2% moisture. Corresponding values in aqueous media were 192 μmol h−1 g−1 dry weight catalyst and 0.8 mM.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1573-0778
    Keywords: Flow cytometry ; hybridoma ; immobilization ; specific antibody productivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In order to determine whether the enhanced specific antibody productivity (q MAb ) of calcium alginate-entrapped hybridoma is cell line-specific, calcium alginate-entrapped hybridomas (4A2 and DB9G8) were cultivated under the condition where we had previously observed significantly enhancedq MAb of calcium alginate-entrapped S3H5/γ2bA2 hybridoma. Unlike S3H5/γ2bA2 hybridoma, neither 4A2 nor DB9G8 hybridomas showed persistently enhancedq MAb when they were entrapped in calcium alginate beads. The enhancedq MAb of entrapped 4A2 and DB9G8 hybridomas, which was 2–3 times higher than theq MAb of free-suspended cells in a control experiment, was observed only during the early stage of the culture. During the early stage of the culture, the viable cell concentration decreased probably due to cell damage during the entrapment process. As cell growth resumed, theq MAb decreased to the similar level ofq MAb of free-suspended cells within 5–7 days. Thus, we conclude that the enhancedq MAb of calcium alginate-entrapped hybridomas is cell line-specific.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1573-0778
    Keywords: growth kinetics ; growth yield ; collagen ; fluidized bed reactor ; immobilization ; alkali supply
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The growth yields for glucose and glutamine of murine hybridoma cells entrapped in collagen gel particles were examined during the growth phase. The immobilized hybridoma cells were cultivated in a fluidized bed fermenter where the medium was circulating to supply oxygen separately. Procedures to supply an alkaline solution for adjusting the pH level strongly affected the growth yields. A direct supply of the alkaline solution to the cultivation system reduced both the growth yields for glucose and glutamine, probably due to a local increase in pH level. On the other hand, when fresh medium in which the pH was adjusted to around 8.5 was added to the cultivation system, the growth yields were unchanged even at the same pH level as when direct alkaline supply was used. These results suggest that an indirect alkaline supply could be recommended to ajust the pH level when using medium-circulating-fermenters.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 10 (1994), S. 55-58 
    ISSN: 1573-0972
    Keywords: Ammonia excretion ; Anabaena azollae (AS-DS) ; Benlate ; immobilization ; MSX ; photobioreactor ; polyvinyl foam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Anabaena azollae (AS-DS), isolated from Azolla filiculoides and grown in nitrogen-free medium, was immobilized in 5-mm-cube polyvinyl foam pieces and incorporated into a photobioreactor system for the production of NH3. NH3 was produced continuously and in significant amounts. Benlate (methyl-1-butyl-carbamoyl)-2-benzimidazole carbamate at 5 ppm and l-methionine-d,l-sulphoximine at 50 μm stimulated NH3 production continuously for a period of 1 week.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 12 (1993), S. 93-98 
    ISSN: 1476-5535
    Keywords: High gravity ; Wheat mash fermentation ; Yeast ; Proline production and excretion ; Osmotic stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The rate of ethanolic fermentation of high gravity wheat mashes bySaccharomyces cerevisiae was increased by nitrogen sources such as ammonium sulfate or arginine. This stimulation was mediated through increased proliferation of cells. Large quantities of proline, however, were excreted by the yeast into the medium when arginine was added as a nutrient supplement. The amount of proline excreted was proportional to the concentration of arginine supplied. Nitrogen sources such as ammonium sulfate or lysine enhanced the production of proline from arginine and its excretion into the medium. Results show that the stimulation of very high gravity fermentation by arginine is not merely through provision of a source of nitrogen but also because it serves as a precursor for the production of proline, a compound which may play a significant role in alleviating the effects of osmotic stress.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 139-144 
    ISSN: 1573-0972
    Keywords: Cheese ; immobilization ; milk-clotting enzymes ; proteases ; rennet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Traditionally, cheese manufacturing is a batch process and current practice is to use a milk-clotting enzyme in a soluble form. Immobilization of proteases for milk coagulation has received renewed interest and potential applications have recently been reported. Use of immobilized proteases would permit renneting of milk as a continuous process. In addition, it should be possible to recover and re-use the enzyme for coagulation of further batches of milk. This review elaborates on the recent developments in the area of immobilized proteases and their application in cheese-making.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 196-201 
    ISSN: 1573-0972
    Keywords: Anabaena doliolum ; calcium ; Chlorella vulgaris ; heavy metals ; immobilization ; magnesium ; organic acids ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The potential of alginate-immobilized Anabaena doliolum and Chlorella vulgaris was assessed for removal of nutrients (NO inf3 sup- and NH inf4 sup+ ) and metals (Cr2O inf7 sup2- and Ni2+) at different biomass concentrations (0.05, 0.1, 0.25, 0.49 and 1.22 g dry wt l-1) and pH values (4 to 10). Though uptake of all these substances was higher in concentrated algal beads (0.25, 0.49 and 1.22 g dry wt l-1), their rate of uptake was significantly (P〈0.001) lower than that of low (0.05 g dry wt l-1) cell density beads. For A. doliolum, there was no significant difference in uptake rates for beads having densities of 0.05 and 0.1 g dry wt l-1. Chlorella vulgaris, however, showed maximum efficiency at 0.1 g dry wt l-1. Uptake of both the nutrients and the metals was maximal at pH 7 followed by pH 8, 6, 9, 10, 5 and 4. Of the different substances (organic acids and divalent cations) used, humic acid was most efficient in decreasing metal uptake. Mg2+ was, however, more efficient than Ca2+ in decreasing Ni2+ uptake. Immobilized algae with a cell density of 0.1 g dry wt l-1 were the most efficient for nutrient and metal removal at pH 6 to 8.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 216-220 
    ISSN: 1573-0972
    Keywords: Aspergillus ; β-fructofuranosidase ; fructo-oligosaccharide ; immobilization ; porous silica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract β-Fructofuranosidase from Aspergillus japonicus MU-2, which produces fructo-oligosaccharides (1-kestose: O-β-D-fructofuranosyl-(2 → 1)-β-D-fructofuranosyl α-D-glucopyranoside); and nystose: O-β-D-fructofuranosyl-(2 → 1)-β-D-fructofuranosyl-(2 → 1)-β-D-fructofuranosyl α-D-glucopyranoside) from sucrose, was immobilized, covalently with glutaraldehyde onto alkylamine porous silica, at high efficiency (64%). Optimum pore diameter of porous silica for immobilization of the enzyme was 91.7 nm. After immobilization, the enzyme's stabilities to temperature, metal ions and proteolysis were improved, while its optimum pH and temperature were unchanged. The highest efficiency of continuous production of fructo-oligosaccharides (more than 60%), using a column packed with the immobilized enzyme, was obtained at 40% to 50% (w/v) sucrose. The half-life of the column during long-term continuous operation at 55°C was 29 days.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 366-371 
    ISSN: 1573-0972
    Keywords: Alginate ; freeze-substitution ; immobilization ; Zymomonas mobilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Alginate-immobilized Zymomonas mobilis cells produced 17.8% (v/v) ethanol in less than 24 h, with an ethanol yield of 97%, compared with 88% for free cells, using a fed-batch cultivation technique. The substrate, glucose, was added intermittently in powder form to foster nucleation of the CO2 formed. Repeated-batch cultivation led to complete utilization of approximately 200 g glucose/l in 7.5 h with a 98% conversion efficiency to ethanol. Free cells used the glucose less efficiently (conversion efficiency of 78%), and even after 100 h the glucose was not fully consumed. Freeze-substitution electron microscopy studies showed that immobilized cells generally displayed lesser blebbing and membrane disruption than free cells. These studies further suggest that membrane blebbing may be due to an effect of high initial glucose levels, and not due to the accumulation of end-products ethanol and CO2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 483-486 
    ISSN: 1573-0972
    Keywords: Acetonitrile ; amides ; biodegradation ; immobilization ; nitriles ; Pseudomonas putida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Pseudomonas putida, capable of utilizing acetonitrile as a sole source of C and N, was immobilized in calcium alginate and the rates of degradation of nitriles, including acetonitrile, and their respective amides were studied. All the organic nitriles and amides tested were converted into NH3 and CO2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 495-502 
    ISSN: 1573-0972
    Keywords: Fungi ; immobilization ; potential applications
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Immobilized cell technology attracts considerable attention because of the many advantages it offers over conventional suspended-cell fermentations. Important advances continue to be made in the potential use of immobilized cells as biocatalysts. This review is mainly devoted to the analysis of recent literature on the applications of immobilized fungal cell systems, ranging from the production or transformation of useful compounds (e.g. organic acids, enzymes, antibiotics, steroids, etc.) to wastewater treatment. The problems and future industrial applications are also discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 9 (1992), S. 229-234 
    ISSN: 1476-5535
    Keywords: Heat shock protein (HSP) ; Yeast ; Saccharomyces ; Viability ; Thermotolerance ; Ethanol tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Heat shock and ethanol stress of brewing yeast strains resulted in the induction of a set of proteins referred to as heat shock proteins (HSPs). At least six strongly induced HSPs were identified in a lager brewing strain and four HSPs in an ale brewing strain. Four of these HSPs with molecular masses of approximately 70, 38, 26 and 23 kDa were also identified in two laboratory strains ofSaccharomyces cerevisiae. The appearance of HSPs correlated with increased survival of strains at elevated temperatures and high concentrations of ethanol. These results suggest that HSPs may play a role in the ethanol and thermotolerance of yeasts. The properties of these proteins and membrane fatty acids in relation to heat and ethanol shock are being investigated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1476-5535
    Keywords: Heat shock ; Ethanol ; Saccharomyces ; Yeast ; Fermentation ; Viability ; Wort
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The effects of heat shock and ethanol stress on the viability of a lager brewing yeast strain during fermentation of high gravity wort were studied. These stress effects resulted in reduced cell viability and inhibition of cell growth during fermentation. Cells were observed to be less tolerant to heat shock during the fermentation of 25°P (degree Plato) wort than cells fermenting 16°P wort. Degree Plato (oP) is the weight of extract (sugar) equivalent to the weight of sucrose in a 100 g solution at 20°C. Relieving the stress effects of ethanol by washing the cells free of culture medium, improved their tolerance to heat shock. Cellular changes in yeast protein composition were observed after 24 h of fermentation at which time more than 2% (v/v) ethanol was present in the growth medium. The synthesis of these proteins was either induced by ethanol or was the result of the transition of cells from exponential phase to stationary phase of growth. No differences were observed in the protein composition of cells fermenting 16°P wort compared to those fermenting 25°P wort. Thus, the differences in the tolerance of these cells to heat shock may be due to the higher ethanol concentration produced in 25°P wort which enhanced their sensitivity to heat shock.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 8 (1992), S. 192-195 
    ISSN: 1573-0972
    Keywords: Covalent linkage ; immobilization ; killer toxin ; nystatin ; Phospholipids ; Signal transduction ; sterols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1573-0778
    Keywords: bioartificial liver ; calcium alginate ; hepatocytes ; immobilization ; non-parenchymal liver cell ; tyrosine aminotransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Hepatocytes and non-parenchymal liver cells were isolated from adult rat liver and co-cultured for 48 hours as a monolayer on polystyrene culture dishes. The ability of tyrosine aminotransferase (TAT) induction in hepatocytes was examined in the presence of dexamethasone and dibutyryl cAMP. Non-parenchymal cells greatly enhance the ability of TAT induction of hepatocytes. A soluble factor with molecular weight of more than 10,000 is responsible for this enhancement, because conditioned medium prepared from non-parenchymal cells is also stimulatory. Non-parenchymal cells restored the ability in hepatocytes damaged with the addition of D-galactosamine. Conditioned medium prepared from non-parenchymal cells treated with D-galactosamine had higher activity of enhancement than the medium from normal cells. The soluble factor might be released in response to some signal of injury. Hepatocytes and non-parenchymal cells were immobilized within Ca-alginate, and although immobilized hepatocytes rapidly lost the ability to induce TAT, hepatocytes co-immobilized with non-parenchymal cells maintained the ability during 4 days of culture. These results indicated that non-parenchymal liver cells, as well as hepatocytes, could be used to construct a bioartificial liver support system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 7 (1991), S. 191-195 
    ISSN: 1476-5535
    Keywords: Yeast ; Trehalose ; Osmotolerance ; Viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A total of 12 yeast strains from various genera were examined for their ability to produce ethanol in the presence of high concentrations of glucose. From these studies, the yeastsTorulaspora delbrueckii andZygosaccharomyces rouxii were observed to the most osmotolerant. These osmotolerant yeast strains were also observed to possess high concentrations of intracellular trehalose. Futhermore, these strains were found to be tolerant to long-term storage at −20°C and to storage at 4°C in beer containing 5% (v/v) ethanol. Cells containing high trehalose levels at the time of freezing or cold storage exhibited the highest cell viabilities. Trehalose concentration was observed to increase during growth on glucose, reaching a maximum after 24–48 h. Increasing the incubation temperature from 21 to 40°C also resulted in an increase in intracellular trehalose content. These results suggest that trehalose plays a role in enhancing yeast survival under environmentally stressful conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 7 (1991), S. 263-268 
    ISSN: 1476-5535
    Keywords: Yeast ; β-Glucanase ; β-Glucosidase catabolite repression ; Sporulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The activities of three glycosidases, β-glucosidase and β(1,3)- and β(1,6)-glucanases have been monitored during growth and blastospore formation inSaccharomycopsis fibuligera. The assays were carried out on the cell-free culture and in a cell-free extract and a wall autolysate preparation from the growing cells. In complex medium containing 1% glucose an increase in the level of all three enzymes was associated with the transition from mycelium to blastospores. When the level of glucose was increased to 5% blastospore formation was repressed and the level of β-glucanases only increased at the end of the fermentation. The β-glucosidase activity increased during the growth phase. In a defined medium in which slow growth in a wholly yeast-like form was observed, growth was not associated with a high level of β-glucanase activity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 7 (1991), S. 35-39 
    ISSN: 1476-5535
    Keywords: 2-Deoxy-d-glucose ; Yeast ; Catabolite repression ; Derepression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The non-metabolizable and toxic glucose analogue 2-deoxy-d-glucose (2-DOG) has been widely employed to screen for regulatory mutants which lack catabolite repression. A number of yeast mutants resistant to 2-DOG have recently been isolated in this laboratory. One such mutant, derived from aSaccharomyces cerevisiae haploid strain, was demonstrated to be derepressed for maltose, galactose and sucrose uptake. Furthermore, kinetic analysis of glucose transport suggested that the high affinity glucose transport system was also derepressed in the mutant strain. In addition, the mutant had an increased intracellular concentration of trehalose relative to the parental strain. These results indicate that the 2-DOG resistant mutant is defective in general glucose repression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1573-0778
    Keywords: high cell density ; ceramic ; BHK ; perfusion system ; immobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A perfusion system which utilizes a porous ceramic core has been tested for the cultivation of transformed BHK cells which produce human transferrin. A design is presented in which cells are immobilized within the porous ceramic particle and are fed by continuous perfusion of batch liquid medium. It was found that more than 5×109 BHK cells could be supported within the 40 mL ceramic matrix, a ten-fold increase in cell density per unit surface area over the standard roller bottle cultures or a five-fold increase in volumetric cell density over suspension cultures. The cell specific productivity of human transferrin was similar to that observed in suspension culture. The system offers the advantages of significant reduction in serum requirements and the potential for scale-up.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1476-5535
    Keywords: Lignocellulosic waste ; Yeast ; Ethanol production ; Optimization study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Hardwood hemicellulose hydrolysate has been utilized as a substrate for ethanol production. Among the three different yeasts tested, the best performances have been obtained, in decreasing order, usingPachysolen tannophilus, Candida shehatae andPichia stipitis. Several pretreatments of this raw material have been studied to improve ethanol yields; in one such pretreatment a strain ofP. tannophilus produced ethanol with a yield of 0.29 gethanol/gsugars (gP/gS); which is only 15% less than the values observed with synthetic media. Neither aeration nor acetone addition improved the fermentation of this substrate; in fact, only a marked stimulation of biomass growth has been observed at the expense of both ethanol and xylitol production.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 4 (1989), S. 315-323 
    ISSN: 1476-5535
    Keywords: Sugar uptake ; Yeast ; Brewer's wort
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary When glucose and fructose are fermented separately, the uptake profiles indicate that both sugars are utilized at similar rates. However, when fermentations are conducted in media containing an equal concentration of glucose and fructose, glucose is utilized at approximately twice the rate of fructose. The preferential uptake of glucose also occurred when sucrose, which was first rapidly hydrolyzed into glucose and fructose by the action of the enzyme invertase, was employed as a substrate. Similar results were observed in the fermentation of brewer's wort and wort containing 30% sucrose and 30% glucose as adjuncts. In addition, the high levels of glucose in the wort exerted severe catabolite repression on maltose utilization in theSaccharmyces uvarum (carlsbergensis) brewing strain. Kinetic analysis of glucose and fructose uptake inSaccharomyces cerevisiae revealed aK m of 1.6 mM for glucose and 20 mM for fructose. Thus, the yeast strain has a higher affinity for glucose than fructose. Growth on glucose or fructose had no repressible effect on the uptake of either sugar. In addition, glucose inhibited fructose uptake by 60% and likewise fructose inhibited, glucose uptake by 40%. These results indicate that glucose and fructose share the same membrane transport components.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 4 (1989), S. 49-53 
    ISSN: 1476-5535
    Keywords: l-Phenylacetyl carbinol ; Saccharomyces cerevisiae ; Yeast ; Benzaldehyde ; Biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The rate of production ofl-phenylacetyl carbinol bySaccharomyces cerevisiae in reaction mixtures containing benzaldehyde with sucrose or pyruvate as cosubstrate was investigated in short 1 h incubations. The effect of yeast dose rate, sucrose and benzaldehyde concentration and pH on the rate of reaction was determined. Maximum biotransformation rates were obtained with concentrations of benzaldehyde, sucrose and yeast of 6 g, 40 g and 60 g/l, respectively. Negligible biotransformation rates were observed at a concentration of 8 g/l benzaldehyde. The reaction had a pH optimum of 4.0–4.5. Rates of bioconversion of benzaldehyde and selected substituted aromatic aldehydes using both sucrose and sodium pyruvate as cosubstrate were compared. The rate of aromatic alcohol production was much higher when sucrose was used rather than pyruvate.o-Tolualdehyde and 1-chlorobenzaldehyde were poor substrates for aromatic carbinol formation although the latter produced significant aromatic alcohol in sucrose-containing media. Yields of 2.74 and 3.80 g/l phenylacetyl carbinol were produced from sucrose and pyruvate, respectively, in a 1 h reaction period.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 4 (1989), S. 81-84 
    ISSN: 1476-5535
    Keywords: Ethanol fermentation ; Wheat starch ; Saccharomyces cerevisiae ; immobilization ; Continuous dynamic immobilized biocatalyst bioreactor ; Biocatalyst bioreactor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A simple and efficient method of conversion of wheat starch B to ethanol was investigated. Employing a two-stage enzymatic saccharification process, 95% of the wheat starch was converted to fermentable sugars in 40 h. From 140 g/l total sugars in the feed solution, 63.6 g/l ethanol was produced continuously with a residence time of 3.3 h in a continuous dynamic immobilized biocatalyst bioreactor by immobilized cells ofSaccharomyces cerevisiae. The advantages and the application of this bioreactor to continuous alcoholic fermentation of industrial substrates are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    ISSN: 1573-0778
    Keywords: alginate ; erythropoietin ; high-density ; immobilization ; microcarrier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Baby hamster kidney (BHK) cells engineered to produce recombinant human erythropoietin (EPO) were cultured at high density on microcarriers entrapped by calcium alginate gel particles. In this system, the BHK cells proliferated not only on the microcarriers but also in vacant spaces in the alginate gel particles. These spaces contributed greatly to high-density cultivation of the cells and a high productivity of EPO.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 3 (1988), S. 9-14 
    ISSN: 1476-5535
    Keywords: Single cell protein ; Sucrose ; Yeast ; Thermotolerance ; Fermentation ; Kluyveromyces marxianus var.marxianus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Amino acid analyses were undertaken on single cell protein (SCP) produced by thermotolerant strains ofKluyveromyces marxianus var.marxianus grown on sugar cane molasses at 40°C. The maximum conversion of available sugars to biomass at 45°C was only 10.8% (g dry wt.·g−1 total sugars). The amino acid composition of the SCP did not differ markedly from that reported for other yeast species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 2 (1988), S. 365-372 
    ISSN: 1476-5535
    Keywords: Osmotic pressure ; Intracellular ethanol ; Yeast ; Nutrient ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The intracellular accumulation of ethanol in yeast and its potential effects on growth and fermentation have been topics of controversy for the past several years. The determination of intracellular ethanol based on the exclusion of [14C]sorbitol to estimate aqueous cell volume was used to examine the question of intracellular ethanol accumulation. An intracellular accumulation of ethanol inSaccharomyces cerevisiae was observed during the early stages of fermentation. However, as fermentation continued, the intracellular and extracellular concentrations of ethanol became similar. Increasing the osmotic pressure of the medium with glucose or sorbitol was observed to cause an increase in the intracellular ethanol concentration. Associated with this was a decrease in yeast growth and fermentation rates. In addition, increasing the osmotic pressure of the medium was observed to cause an increase in glycerol production. Supplementation of the media with excess peptone, yeast extract, magnesium sulfate and potassium phosphate was found to relieve the detrimental effects of high osmotic pressure. Under these conditions, though, no effect on the intracellular and extracellular ethanol distribution was observed. These results indicate that nutrient limitation, and not necessarily intracellular ethanol accumulation, plays a key role during yeast fermentations in media of high osmolarity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1573-0778
    Keywords: hybridoma ; immobilization ; monoclonal antibodies ; perfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A fixed bed perfusion system for hybridoma cell immobilization is presented. The system consists of a culturing vessel (300 ml total volume) in which polyurethane (PU) sponges in the form of small cubes of about 5 mm sides are packed. Cells are immobilized by physical entrapment in the foam matrix. By entrapment of the cells in the pores of the matrix high cell concentration can be maintained in a mechanically protected environment. Medium is continuously circulated by an airlift pump mounted in the cell-free chamber (700 ml total volume). Medium flow rate, feeding rate, dissolved oxygen, pH, nutrient uptake and waste product formation can be easily monitored and controlled. Steady state conditions are established with medium dilution rates of 1.0–1.5 reactor volume per day. The steady state is characterized by a constant cell density, constant culture volume and constant glucose and lactate levels. Cell-free supernatant is collected continuously in a cold room adjacent to the 37°C culture room. Monoclonal antibodies (MAb) are produced at a concentration of 150–200 μg/ml for several weeks. An important feature of the system is the capacity to maintain a population of cells after the growth phase in a non-proliferating state for extended time periods expressing high titers of MAb.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 2 (1987), S. 59-62 
    ISSN: 1476-5535
    Keywords: Yeast ; Zygosaccharomyces ; Spoilage ; Synergism ; pH ; °Brix
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A quantitative method for the prediction of growth of the food spoilage yeastZygosaccharomyces bailii in a model fruit-drink system is described. A factorially designed experiment was employed to produce polynomial equations relating pH and sugar concentration (°brix) to the lag period and doubling time of this yeast. Low pH values (〈3.0) and high °brix values (〉40) show a strong synergistic action on the extension of lag period, which could be used, along with the model presented, in the formulation of product preservation systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 2 (1987), S. 159-165 
    ISSN: 1476-5535
    Keywords: Yeast ; Genetic stability ; Saccharomyces cerevisiae ; Selection ; Reproductive fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The potential for changes in allele frequencies in yeast populations by selection was examined. Cells from the wine yeastSaccharomyces cerevisiae (strain Montrachet) were grown over a large number of generations using two different culturing techniques, each with two variations: serial transfers on WLN agar plates with and without UV irradiation, and continuous culture in autoclaved and in filter-sterilized grape must. A low frequency of variant isozyme patterns was found in samples taken at the end of the experiment. Growth rates in must and on agar plates were also examined, and it was found that all samples were faster-growing than the original strain, to varying degrees. Applications for the selection system developed are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 2 (1987), S. 79-85 
    ISSN: 1476-5535
    Keywords: Yeast ; Bacteria ; High cell density ; Oxygen transfer ; Heat transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary High-productivity continuous fermentation processes have been developed for the production of important industrial microorganisms in specially designed fermentors.Saccharomyces cerevisiae, Pichia pastoris, Kluyveromyces fragilis, andCandida utilis yeasts have been grown in bench-scale fermentors at cell densities of over 120 g/l, whileEscherichia coli, Bacillus megaterium, Methylomonas sp. andPseudomonas putida bacteria have been cultivated to cell densities of more than 110 g/l. Productivities (g cells per 1 per h) greater than 25 have been achieved in both bench-scale and 1500-liter fermentors with yeasts, and values as high as 55 have been achieved with bacteria in the bench-scale fermentor. The microorganisms were grown on defined media using ammonia for pH control and as nitrogen source. The fermentor, capable of high oxygen and heat transfer rates, was operated at constant volume with continuous feed and product discharge. The high-productivity process reduces fermentor size, media sterilization requirements, and may under some circumstances eliminate waste and recycle streams. It can also be applied to a variety of biological products.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 2 (1987), S. 167-174 
    ISSN: 1476-5535
    Keywords: Selection ; Yeast ; Fitness distribution ; Mutation ; Saccharomyces cerevisiae ; Computer simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The fitness distribution of new mutations inSaccharomyces cerevisiae strain Montrachet was determined for cells on agar irradiated for four periods of time with ultraviolet light. The fitness distributions were obtained by converting a large number of colony diameters into relative fitnesses. The distributions were then used to perform a computer simulation with the purpose of predicting the potential of a stock culture to increase in general fitness through selection, given a frequency and magnitude of mutations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...