ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Optimization of operating temperature for continuous glucose isomerase reactor system (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 24 (1982), S. 1889-1896 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260240816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effect of air supplement on the performance of continuous ethanol fermentation system (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 12-16 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For the purpose of improving ethanol productivity, the effect of air supplement on the performance of continuous ethanol fermentation system was studied. The effect of oxygen supplement on yeast concentration, cell yield, cell viability, extracellular ethanol concentration, ethanol yield, maintenance coefficient, specific rates of glucose assimilation, ethanol production, and ethanol productivity have been evaluated, using a high alcohol tolerant Saccharomyces cerevisiae STV89 strain and employing a continuous fermentor equipped with an accurate air metering system in the flow rate range 0-11 mL air/L/h. It was found that, when a small amount of oxygen up to about 80μ mol oxygen/L/h was supplied, the ethanol productivity was significantly enhanced as compared to the productivity of the culture without any air supplement. It was also found that the oxygen supplement improved cell viability considerably as well as the ethanol tolerance level of yeast. As the air supply rate was increased, from 0 to 11 mL air/L/h while maintaining a constant dilution rate at about 0.06 h-1, the cell concentration increased from 2.3 to 8.2 g/L and the ethanol productivity increased from 1.7 to 4.1 g ethanol/L/h, although the specific ethanol production rate decreased slightly from 0.75 to 0.5 g ethanol/g cell/h. The ethanol yield was slightly improved also with an increase in air supply rate, from about 0.37 to 0.45 ethanol/g glucose. The maintenance coefficient increased by only a small amount with the air supplement. This kind of air supplement technique may very well prove to be of practical importance to a development of a highly productive ethanol fermentation process system especially as a combined system with a high density cell culture technique.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Mathematical modeling for mixed culture growth of two bacterial populations with opposite substrate preferences (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 31 (1988), S. 144-159 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An unstructured mathematical model is proposed for mixed culture growth of two different bacterial species that exhibit “opposite” substrate preferences in response to the “same” environmental conditions. The model incorporates enzymatic control mechanisms such as induction, repression, and inhibition in the microorganisms as manifested in their preferential utilization of substrates and microbial interactions such as amensalism and competition. The model predicts cell mass, substrate concentrations, dissolved oxygen tension, as well as key enzyme levels. The predictions of the model are compared with experimental data for pure culture growth and for mixed culture growth on two substrates, glucose and citrate, in a batch reactor.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260310208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Continuous production of gluconic acid and sorbitol from Jerusalem artichoke and glucose using an oxidoreductase of Zymomonas mobilis and inulinase (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 336-342 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gluconic acid and sorbitol were simultaneously produced from glucose and Jerusalem artichoke using a glucose-fructose oxidoreductase of Zymomonas mobilis and inulinase. Inulinase was immobilized on chitin by cross-linking with glutaraldehyde. Cells of Z. mobilis permeabilized with toluene were coimmobilized with chitin-immobilized inulinase in alginate beads. The optimum amounts of both chitin-immobilized inulinase and permeabilized cells for coimmobilization were determined, and operational conditions were optimized. In a continuous stirred tank reactor operation, the maximum productivities for gluconic acid and sorbitol were about 19.2 and 21.3 g/L/h, respectively, at the dilution rate of 0.23 h-1 and the substrate concentration of 20%, but operational stability was low because of the abrasion of the beads. As an approach to increase the operational stability, a recycle packed-bed reactor (RPBR) was employed. In RPBR operation, the maximum productivities for gluconic acid and sorbitol were found to be 23.4 and 26.0 g/L/h, respectively, at the dilution rate of 0.35 h-1 and the substrate concentration of 20% when the recirculation rate was fixed at 900 mL/h. Coimmobilized enzymes were stable for 250 h in a recycle packed-bed reactor without any loss of activity, while half-life in a continuous stirred tank reactor (CSTR) was observed to be about 150 h.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Enzymatic production of cyclodextrins from milled corn starch in an ultrafiltration membrane bioreactor (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 88-94 
    Details
    ISSN: 0006-3592
    Keywords: cyclodextrins ; cyclodextrin glycosyltransferase (CGTase) ; product inhibition ; ultrafiltration membrane bioreactor ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Cyclodextrin glycosyltransferase (CGTase) was found to be severely inhibited by cyclodextrins. In order to increase the conversion yield by reducing product inhibition and reuse the CGTase in the production of cyclodextrins from milled corn starch, an ultrafiltration membrane bioreactor system was employed. In a batch operation with ultrafiltration, the conversion yield was increased 57% compared with that without ultrafiltration. Operating conditions for the continuous production of cyclodextrins in the membrane bioreactor were optimized by taking into consideration the filtration rate and the conversion yield as follows: initial starch concentration, 7% (w/v); starch feeding rate, 240 mg/h; CGTase loading, 350 units/initial gram starch. When cyclodextrins were continuously produced in the membrane bioreactor under optimized conditions, 340 units of CGTase was require to produce 1 g of cyclodextrins for 48 h, while in the case of conventional batch operation, 1 g of cyclodextrins was produced for 24 h by 1410 units of CGTase. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Growth kinetics of the photosynthetic bacterium Chlorobium thiosulfatophilum in a fed-batch reactor (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 583-592 
    Details
    ISSN: 0006-3592
    Keywords: H2S removel ; photosynthetic bacteria ; growth kinetics ; fed-batch reactor ; light attenuation effect ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Hydrogen sulfide dissolved in water can be converted to elementary sulfur or sulfate by the photosynthetic bacterium Chlorobium thiosulfatophilum. Substrate inhibition occurred at sulfide concentrations above 5.7 mM. Light inhibition was found at average light intensities of 40,000 lux in a sulfide concentration of 5 mM, where no substrate inhibition occurred. Light intensity, the most important growth parameter, was attenuated through both scattering by sulfur particles and absorption by the cells. Average cell and sulfur particle sizes were 1.1 and 9.4 μm, respectively. Cells contributed 10 times as much to the turbidity as sulfur particles of the same weight concentration. The light attenuation factor was mathematically modeled, considering both the absorption and scattering effects based on the Beer-Lambert law and the Rayleigh theory, which were introduced to the cell growth model. Optimal operational conditions relating feed rate vs. light intensity were obtained to suppress the accumulation of sulfate and sulfide and save light energy for 2- and 4-L fed-batch reactors. Light intensity should be greater for the same performance (H2S removal rate/unit cell concentration) in larger reactors due to the scaleup effect on light transmission. Knowledge of appropriate growth kinetics in photosynthetic fed-batch reactors was essential to increase feed rate and light intensity and therefore cell growth. A mathematical model was developed that describes the cell growth by considering the light attenuation factor due to scattering and absorption and the crowding effect of the cells. This model was in good agreement with the experimental results. © 1992 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260400505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Effect of the hydration state of supports before lyophilization on subtilisin-A activity in organic media (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 50 (1996), S. 687-692 
    Details
    ISSN: 0006-3592
    Keywords: hydration state of support ; colyophilized enzyme ; lyophilization ; subtilisin-A ; enzymatic optical resolution ; organic solvent ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Subtilisin-A was colyophilized with various types of support materials, such as Amberlite IRC-50, Celite545, chitosan, DEAE-cellulose, DOWEX-1, zeolite, glass bead, and polystyrene. The colyophilized enzyme was used for the optical resolution of racemic 1-phenylethylamine with 2,2,2-trifluoroethylbutyrate in 3-methyl-3-pentanol. The enzyme activity in organic media changed dramatically according to the hydration state of the support materials before lyophilization. This effect was especially marked with supports of high water capacity (aquaphilicity), such as chitosan and DEAE-cellulose. By hydrating these supports of high aquaphilicity prior to lyophilization, subtilisin-A activity in organic media increased ca. 4-8 times, depending upon the supports used. This result suggests that the hydration state of aquaphilic support materials for colyophilization is critical to determining enzyme activity in organic solvents. © 1996 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 8
    Electronic Resource
    Electronic Resource
    Clonal variability within dihydrofolate reductase-mediated gene amplified Chinese hamster ovary cells: Stability in the absence of selective pressure (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 60 (1998), S. 679-688 
    Details
    ISSN: 0006-3592
    Keywords: chimeric antibody ; CHO cells ; clonal analysis ; dihydrofolate reductase ; gene amplification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Recombinant Chinese hamster ovary (rCHO) cells expressing a high level of chimeric antibody were obtained by cotransfection of heavy- and light-chain cDNA expression vectors into dihydrofolate reductase-deficient CHO cells and subsequent gene amplification in medium containing stepwise increments in methotrexate (MTX) level up to 1.0 μM. To determine the clonal variability within the amplified cell population in regard to antibody production stability, 20 subclones were randomly isolated from the amplified cell population at 1.0 μM MTX (CS13-1.0 cells). Clonal analysis showed that CS13-1.0 cells were heterogeneous with regard to specific growth rate (μ) and specific antibody productivity (qAb), although they were derived from a single clone. The μ and qAb of 20 subclones were in the range of 0.51 to 0.72 day-1 and 10.9 to 19.1 μg/106 cells/day, respectively. During 8 weeks of cultivation in the absence of selective pressure, the μ of most subclones did not change significantly. On the other hand, their qAb decreased significantly. Furthermore, the relative decrease in qAb varied among subclones, ranging from 30% to 80%. Southern and Northern blot analyses showed that this decreased qAb resulted mainly from the loss of amplified immunoglobulin (Ig) gene copies and their respective cytoplasmic mRNAs. For the sake of screening convenience, an attempted was made to correlate the initial properties of subclones (such as μ, qAb, and Ig gene copies) with their antibody production stability during long-term culture. Among these initial properties examined, only qAb of subclones could help to predict their stability to some extent. The subclones with high qAb were relatively stable with regard to antibody production during long-term culture in the absence of selective pressure (P 〈 0.005, ANOVA). Taken together, the clonal heterogeneity in an amplified CHO cell population necessitates clonal analysis for screening stable clones with high qAb. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 679-688, 1998.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 9
    Electronic Resource
    Electronic Resource
    Increase of xylitol production rate by controlling redox potential in Candida parapsilosis (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 58 (1998), S. 440-444 
    Details
    ISSN: 0006-3592
    Keywords: xylitol production ; redox potential ; dissolved oxygen ; Candida parapsilosis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of redox potential on xylitol production by Candida parapsilosis was investigated. The redox potential was found to be useful for monitoring the dissolved oxygen (DO) level in culture media, especially when the DO level was low. An increase in the agitation speed in a 5 L fermentor resulted in an increased culture redox potential as well as enhanced cell growth. Production of xylitol was maximized at a redox potential of 100 mV. As the initial cell concentration increased from 8 g/L to 30 g/L, the volumetric productivity of xylitol increased from 1.38 g/L · h to 4.62 g/L · h. A two-stage xylitol production strategy was devised, with stage 1 involving rapid production of cells under well-aerated conditions, and stage 2 involving cultivation with reduced aeration such that the culture redox potential was 100 mV. Using this technique, a final xylitol concentration of 180 g/L was obtained from a culture medium totally containing 254.5 g/L xylose in a 3,000 L pilot scale fermentor after 77 h fermentation. The volumetric productivity of xylitol during the fermentation was 2.34 g/L · h. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58:440-444, 1998.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 10
    Electronic Resource
    Electronic Resource
    Characterization of chimeric antibody producing CHO cells in the course of dihydrofolate reductase-mediated gene amplification and their stability in the absence of selective pressure (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 58 (1998), S. 73-84 
    Details
    ISSN: 0006-3592
    Keywords: chimeric antibody ; CHO cells ; dihydrofolate reductase ; flow cytometry ; gene copy number ; stability ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Recombinant Chinese hamster ovary (CHO) cells expressing a high-level of chimeric antibody against S surface antigen of hepatitis B virus were obtained by co-transfection of heavy and light chain cDNA expression vectors into dihydrofolate reductase (dhfr)-deficient CHO cells and subsequent gene amplification in medium containing stepwise increments in methotrexate (MTX) level such as 0.02, 0.08, 0.32, 1.0, and 4.0 μM. The highest producer (HP) subclone was isolated from each MTX level and was characterized with respect to cell growth and antibody production in the corresponding level of MTX. The specific growth rate of the HP subclone was inversely proportional to the MTX level. On the other hand, its specific antibody productivity (qAb) rapidly increased with increasing MTX level up to 0.08 μM, and thereafter, it gradually increased to 20 μg/106 cells/day at 4 μM MTX. Southern blot analysis showed that the enhanced qAb at higher MTX level resulted from immunoglobulin (Ig) gene amplification. The stability of the HP subclones isolated at 0.02, 0.08, 0.32, and 1.0 μM MTX in regard to antibody production was investigated during long-term culture in the absence of MTX. The qAb of all subclones significantly decreased during the culture. However, the relative extent of decrease in qAb was variable among the subclones. The HP subclone isolated at 1 μM MTX was most stable and could retain 59% of the initial qAb after 80 days of cultivation. Southern blot analysis showed that this decrease in qAb of the subclones resulted mainly from the loss of Ig gene copies during long-term culture. Despite the decreased qAb, the HP subclone isolated at 1 μM MTX could maintain high volumetric antibody productivity over three months because of improved cell growth rate during long-term culture. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58:73-84, 1998.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...