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
Filter
  • Organic Chemistry  (118)
  • Biochemistry and Biotechnology  (25)
  • Wiley-Blackwell  (143)
  • 1
    Electronic Resource
    Electronic Resource
    Stereoselective bioconversions in continuously operated fixed bed reactors: Modeling and process optimization (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 52 (1996), S. 459-471 
    Details
    ISSN: 0006-3592
    Keywords: continuous kinetic resolution ; fixed bed reactors ; mathematical modeling ; lipases ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The nonaqueous lipase-catalyzed kinetic resolution of racemic 2-methyl-1-pentanol in a continuously operated fixed bed reactor was theoretically and experimentally studied. A 2-dimensional mathematical model was developed to predict the performance of the heterogeneous enantioselective biotransformation and to optimize the productivity and effective stereoselectivity of the process by taking pore diffusion, solid(SINGLEBOND)liquid mass transfer, convection, and axial dispersion into account. Experimental investigations were conducted with lipase from Pseudomonas sp. immobilized by ionic binding in the pores of the anion exchange resin Duolite A 568. As determined in prior initial rate experiments, the specific activities of the immobilized lipase were maximal at a water activity of approximately aw = 0.67 and revealed a significant dependence on the amount of enzyme bound to the carrier material, with enantiomeric ratios slightly increasing with increasing water activities. Continuous resolution processes were carried out at a wide range of enzyme loadings. By controlled immobilization according to the theoretically evaluated optimal enzyme loading, the continuous racemic resolution could be optimized to obtain (R)-2-methyl-1-pentanol at high productivity and enantiopurity (ee 〉 95%). The steady-state characteristics of the system could be generally predicted by the model, despite the necessity to reevaluate the kinetic properties of the immobilized lipase to account for the complex non-aqueous microkinetics in a heterogeneous environment. Further model extension introducing competitive inhibition of free water in solutions as well as water diffusion and adsorption to the biocatalyst were useful in providing a more accurate description of the experimental results. © 1996 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    Phospholipase-C from Bacillus cereus: Production, purification, and properties (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 551-560 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A substrain of Bacillus cereus 569/H produced under controlled fermentation conditions in a pilot plant fermentor phospholipase-C. A partially purified preparation showed good storage stability as a lyophylized powder and in frozen solutions. The preparation contained very small amounts of phosphomonoesterase and proteolytic activities and essentially no ribonuclease activity. The level of hemolytic activity of the preparation was much lower than that of a commercial preparation of phospholipase-C from Clostridium. Treatment of sarcoplasmic reticulum membrane with phospholipase-C from B. cereus and from Clostridium showed that the B. cereus enzyme caused hydrolysis of 96% of the membrane phospholipids whereas the enzyme from Clostridium could hydrolyze only 80% of the phospholipids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260150310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Determination of antibody content in live versus dead hybridoma cells: Analysis of antibody production in osmotically stressed cultures (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 947-964 
    Details
    ISSN: 0006-3592
    Keywords: hybridoma cells ; antibody production ; flow cytometry ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Hybridomas are known to exhibit increased specific antibody production rated when subjected to environmental stress. Under these conditions, viability is low so that population-average measurements do not properly reflect the state of viable cells. Even for flow cytometry, which gives a population distribution, special techniques must be used to discriminate between viable and nonviable cells. We describe the use of the vital stain ethidium monoazide (EMA) for independent measurement of intracellular antibody content in live and dead cells via flow cytometry. EMA is shown to be superior to light scattering techniques in identifying dead cells. We apply this technique to show that, in control batch culture, the specific antibody prodution rate and antibody content in live cells are constant during exponential growth, but decrease as cells enter the stationary phase. Antibody is retained in dead cells, but at a lower level than in live cells. We further show that, under hyperosmotic stress, the specific antibody production rate and antibody content in live both remain high during death phase. © 1992 John Wiley & Sons, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260400811
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Damaging agitation intensities increase DNA synthesis rate and alter cell-cycle phase distributions of CHO cells (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 978-990 
    Details
    ISSN: 0006-3592
    Keywords: DNA synthesis rate ; agitation ; cell-cycle kinetics ; flow cytometry ; cell culture ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of fluid-mechanical force (agitation) on the cell cycle kinetics of Chinese hamster ovary (CHO) cells cultured in suspension in 2-L bioreactors has been examined. A two-color flow cytometry method was used to determine the fraction rate of DNA synthesis. With increased agitation intensity, cell viability decreased as a result of increased cell death. However, increased agitation induced the viable cells of the culture to a higher proliferative state relative to a control culture. The fraction of viable cells of the high-agitation culture (250 rpm) in S phase was higher (up to 45%) and in G1 phase was lower (up to 50%) compared with the viable cells of the control culture (80 rpm). The DNA synthesis rate per viable S-phase cell of the high-agitation culture was confirmed by recovery experiments, which were conducted to measure the apparent specific growth rate and the cell cycle kinetics of the high-agitation culture upon reduction in the agitation rate from 250 rpm back to 80 rpm. The apparent specific growth rate of the test culture, calculated for the first 12 h of the recovery period, was greater than the apparent specific growth rate of the control culture. Furthermore, the proliferative state of the viable cells of the test culture, which had become higher relative to the control culture during the high agitation period, gradually approached the level of the control culture during recovery. Results also show that the magnitude of the agitation intensity; the culture agitated at 250 rpm attained a greater proliferative state than a parallel culture agitated at 235 rpm. The 250-rpm culture had a higher fraction of S-phase and a lower fraction of G1-phase cells than the 235-rpm culture. The DNA sunthesis rate per viable S-phase cell of the 250-rpm culture was greater than of the 235-rpm culture. © 1992 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260400814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Large scale synthesis of dinucleoside monophosphates catalyzed by ribonuclease from Aspergillus clavatus (1972)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 14 (1972), S. 861-870 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A gram scale enzymatic synthesis of eight, dinucleoside monophosphates (ApC, ApU, CpC, CpU, GpC, GpU, UpC, and UpU) is described. The synthesis involves a reaction between the appropriate ribonucleoside-2′,3′-cyclie phosphates and cytidine or uridine in the presence of ribonuelease from Aspergillus clavatus at 30°C. The enzyme is removed from the reaction mixture by chromatography on Bio-Gel P-4, and the dinucleoside monophosphate is further purified by chromatography on a DEAE-Sephadex A-25, column.A procedure for the large scale preparation of the ribonuclease from Aspergillus clavatus is also described.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260140602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    An integrated microprocessor-based fermenter control system (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 494-503 
    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 integrated microprocessor-based fermenter controller was developed in 1980 for an operational environment at Cetus Corp. The main goals in the design and construction of the system were (1) to facilitate scale-up; (2) to provide flexibility and high performance for optimizing fermentation processes; and (3) to be cost-effective for 15 in-house systems. It was also developed to work in conjunction with a laboratory minicomputer for on-line optimization experiments. The controller controls temperature, agitation, dissolved oxygen, pH, and foam throughout each fermentation run without manual intervention. The feedback control parameters have been optimized to provide very accurate control over a wide range of setpoint conditions and under rapidly changing metabolic conditions such as induced during an Escherichia coli batch run. The controller has also been configured to monitor, display, and record each of the controlled variables; support the interactive operator console; and communicate with the laboratory computer. In over 4 years of operation, these systems have met the design goals and have proven to be very reliable. The controller is described, its operational performance presented, and a typical fermentation run delineated.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260280405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A modified procedure for the large scale preparation of tRNA from E. coli (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1081-1088 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A procedure for the preparation of about 50 g batches of tRNA from 25 kg E. coli W is described. The method involves phenolic extraction of the cells, batch absorption of the tRNA on DEAE-cellulose, washing the DEAE-cellulose and packing it into a column, elution of the tRNA from the column and precipitation of the tRNA with ethanol. The method is less time and labor consuming than the methods described in the literature and can be carried out with relatively simple equipment.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260150607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    High-yield growth of E. coli at different temperatures in a bench scale fermentor (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 227-239 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: E. coli wax grown exponentially at different temperatures in a bench scale fermentor. pH was maintained at 6.8 by ammonia which served also as the nitrogen source. Glucose was introduced semi-continuously at a predetermined rate which ensured a glucose concentration of 25-50 g/liter during growth. The culture was sparged with pure oxygen.Yield constants for glucose, nitrogen, phosphorus, and oxygen were determined at the different temperatures of propagation.When all growth conditions, except temperature, were kept constant, the maximal possible yield of exponentially grown cell mass was found to be directly proportional to the doubling time. Concentrations of up to 55 g dry cells/liter culture were achieved.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260170208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Dense growth of aerobic bacteria in a bench-scale fermentor (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 18 (1976), S. 81-94 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Escherichia coli B, Escherichia coli MRE 600, Escherichia coli K 12-3300, Pseudomonas fluorescens, and Aerobacter aerogenes were grown exponentially in a bench-scale fermentor to cell concentrations in the range of 20 to 41 g dry cells/liter at 30°C and 30 to 55 g dry cells/liter at 25°C. The high cell concentrations were achieved in a growth system previously described for growth of Escherichia coli W (Biotechnol. Bioeng., 16, 933 (1974); ibid. 17, 227 (1975)). Various enzyme activity levels in the high-concentration cells were compared to those in cells grown in conventional low-density cultures. No significant differences were found. The culture supernatants were found to be essentially free of high-molecular weight metabolic or cell lysis products. Yield constants for glucose, nitrogen, oxygen, and phosphorus were also determined in the dense cultures and some of their relations to the growth conditions are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260180107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Pilot scale exponential growth of Escherichia coli W to high cell concentration with temperature variation (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 18 (1976), S. 839-846 
    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 efficient method to grow Escherichia coli W to high cell concentrations on the pilot scale is described and discussed. The method involves growth linked introduction of glucose; and ammonia to the culture, sparing with oxygen, and maintenance of aerobic conditions by gradually decreasing the temperature in the culture in order to keep the oxygen demand within the limits of the capacity of supply. Under these conditions the linear rate of cell mass production is actually the result of exponential growth with a gradually decreasing growth-rate constant.About 10 kg packed cells were produced in a 50 liter working-volume fermentor in one run of 13 hr. The concentration of the cells at the end of the growth was about 47 g dry cells/liter. The expenditure for nutrients was minimal and the controls were of simple automatic nature. From the determined yield constants for glucose, nitrogen, phosphorus, and oxygen it may be inferred that the cells grown by this method are similar to those grown exponentially at constant temperature.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260180606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...