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
  • Biochemistry and Biotechnology  (11)
  • 1995-1999  (10)
  • 1960-1964  (1)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Control of heterotrophic layer formation on nitrifying biofilms in a biofilm airlift suspension reactor (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 53 (1997), S. 397-405 
    Details
    ISSN: 0006-3592
    Keywords: airlift reactor ; biofilm ; biofilm detachment ; control biofilm formation ; heterotrophic layer ; hydraulic retention time ; nitrification ; oxygen diffusion limitation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A Biofilm Airlift Suspension (BAS) reactor was operated with nitrifying biofilm growth and heterotrophic suspended growth, simultaneously converting ammonium and acetate. Growth of heterotrophs in suspension decreases the diffusion limitation for the nitrifiers, and enlarges the nitrifying capacity of a biofilm reactor. Neither nitrifiers nor heterotrophs suffer from additional oxygen diffusion limitation when the heterotrophs grow in suspension. Control of the location of heterotrophic growth, either in suspension or in biofilms over the nitrifying biofilms, was possible by manipulation of the hydraulic retention time. A time delay for formation and disappearance of the heterotrophic biofilms of 10 to 15 days was observed. Surprisingly, it was found that in the presence of the heterotrophic layers the maximum specific activity on ammonia of the nitrifying biofilms increased. The reason for the increase in activity is unknown. The effect of heterotrophic biofilm formation on oxygen diffusion limitation for the nitrifiers is discussed. Some phenomena compensating the increased mass transfer resistance due to the growth of a heterotrophic layer are also presented. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 397-405, 1997.
    Additional Material: 6 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
    Rheologies and morphologies of three actinomycetes in submerged culture (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 80-85 
    Details
    ISSN: 0006-3592
    Keywords: rheology ; morphology ; actinomycete ; Saccharopolyspora erythraea ; Actinomadura roseorufa ; Streptomyces rimosus ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The broth rheologies and morphologies of three actinomycetes (Saccharopolyspora erythraea, Actinomadura roseorufa, and Streptomyces rimosus) in submerged culture have been examined. The rheology of all the broths became pseudoplastic as soon as significant growth occurred with the power law index, n, falling to 0.20 to 0.25. The consistency index, K, rose with biomass concentration although in some instances it fell later in the fermentation. The mean main hyphal lengths of all cultures were in the range, 15 to 25 μm, and did not alter greatly even when large changes in K were occurring. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Operational patterns affecting lactic acid production in ultrafiltration cell recycle bioreactor (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 320-327 
    Details
    ISSN: 0006-3592
    Keywords: cell recycle reactor ; ultrafiltration tubular membranes ; high lactic acid productivities ; best operational conditions ; different dilution rates ; start-up strategy ; membrane permeability ; long-term fermentations ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Lactic acid production with cell recycling on an ultrafiltration tubular membrane reactor was studied; higher lactic acid concentrations as well as productivities were obtained under long-term fermentations compared with other high cell density systems. Different operational conditions, namely dilution rates and start-up modes, were assessed. Performances were very different at the three different dilution rates tested (D = 0.20 h-1, D = 0.40 h-1, or D = 0.58 h-1). The different behaviours are discussed and factors responsible for them are presented. The best way to operate for lactic acid production is chosen, the dilution rate of D = 0.40 h-1 being the one providing the best overall performance. On the other hand, results show that of the two start-up modes tested, continuous start (membrane open) permits higher permeabilities throughout the operational runs than batch start (membrane closed). Operational stability was found to be directly associated with membranes that work at “steady state,” the membrane permeability being kept around 15 L/m2 h. Optimized cell bleed can improve time of operation if such membrane permeability can be maintained for a longer time. A comparison of results with those obtained in other lactic acid production systems is presented; such comparison shows that this tubular ultrafiltration membrane cell recycle reactor presents three important advantages: (1) concomitant lactic acid concentrations and productivities; (2) long periods of operation at reasonable permeabilities; and (3) good mechanical stability permitting the use of steam sterilization. © 1995 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450406
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Polyphenoloxidases immobilized in organic gels: Properties and applications in the detoxification of aromatic compounds (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 48 (1995), S. 585-591 
    Details
    ISSN: 0006-3592
    Keywords: phenoloxidases ; enzyme immobilization ; reverse micelles ; organic gels ; biotic detoxification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gelatine gels originate from water in oil microemulsions in which the ternary system consists of isooctane/ sulfosuccinic acid bis [2-ethyl hexyl] ester/water; the solubilization of gelatin in the water pool of these microemulsions transforms them into viscous gels in which it is possible to cosolubilize various reactive molecules. These gels were used to immobilize two phenoloxidases, a laccase from Trametes versicolor and a tyrosinase from mushroom. The best balance between gel retention and catalytic activity was reached at a gelatine concentration of 2.5% (w/v) in the case of tyrosinase, while laccase immobilization was independent of gelatine concentration. Both enzymes kept the same optimum pH as the corresponding soluble controls, while a partial loss of activity was observed when they were immobilized. Immobilized enzymes showed an increased stability when incubated for several days at 4°C with a very low release from the gels in the incubation solutions. The immobilization of tyrosinase and of laccase enhanced stability to thermal inactivation. Furthermore, gel-entrapped tyrosinase was almost completely preserved from proteolysis: more than 80% of the activity was maintained, while only 25% of the soluble control activity was detected after the same proteolytic treatments. A column packed with gel-immobilized tyrosinase was used to demonstrate that enzymes immobilized with this technique may be reused several times in the same reaction without loosing their efficiency. Finally, gel-entrapped tyrosinase and laccase were capable of removing naturally occurring and xeno-biotic aromatic compounds from aqueous suspensions with different degrees of efficiency. © 1995 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260480605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Studies on the purification of vaccinia virusIn conducting the research reported herein, the investigators adhered to “Principles of Laboratory Animal Care,” as established by the National Society for Medical Research. (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 6 (1964), S. 321-328 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Various methods for the removal of extraneous matter from vaccinia virus suspensions are described and compared. Of ten procedures tested, differential centrifugation and Freon extraction were the most successful. Both the partially purified suspensions and the dried products prepared from them had high virus titers in embryonated eggs and high infectivity for mice. Although both processes resulted in products with the same titers, the differentially centrifuged product was approximately tenfold more purified as shown by the percentage solids of the suspensions before freeze drying.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260060307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The primary production of an infectious recombinant Herpes Simplex Virus vaccine (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 57 (1998), S. 262-271 
    Details
    ISSN: 0006-3592
    Keywords: Herpes Simplex Virus type 2 ; DISC HSV-2 ; heparin ; dextran sulphate ; cell rupture ; virus release ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The production and extracellular release of a recombinant Herpes Simplex Virus (type 2) from monolayers of infected complementing Vero cells (CR2) are addressed. Growth and virus production conditions are identified that provide adequate virus titers with cell seeding densities and viral multiplicities of infection that could be reasonably handled in manufacturing. Harvesting by sonication of cell monolayers is shown to give the highest recovery of infectious virus (to 2.5 × 106 pfu/mL) but leads to process stream contamination by cellular proteins through the rupturing of cells (to 28 pg protein/pfu). By comparison, freeze-thaw cycles and osmotic rupture by hypotonic saline or glycerol shock procedures yield only low virus recovery (typically 〈10% of that by sonication), and are accompanied by yet higher levels of protein contamination (up to 30-fold higher pg protein/pfu). Addition of the polyanionic polymers, heparin or dextran sulphate to a harvest using either hypotonic saline, glycerol shock or isotonic phosphate buffered saline increased the yield of infectious virus in the supernatant. By contrast, addition of polycationic poly-l-lysine resulted in negligible increase in the supernatant virus titer. The highest virus titers (4.7 × 107 pfu/mL) were achieved following treatment of roller bottle cultured cells displaying a high cytopathic effect with heparin at 50 μg/mL for at least 3 h post harvest. This procedure also gave the lowest levels of protein contamination (〈2 pg protein/pfu). The fivefold lower yield of infectious virus from cultures displaying a low cytopathic effect (〈70% CPE) indicates the importance of cell physiological state at harvest. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 262-271, 1998.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    Enzymatic synthesis of a CCK-8 tripeptide fragment in organic media (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 50 (1996), S. 700-708 
    Details
    ISSN: 0006-3592
    Keywords: α-chymotrypsin ; organic media ; tripeptide synthesis ; CCK-8 ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The enzymatic synthesis of the tripeptide derivative Z-Gly-Trp-Met-OEt is reported. This tripeptide is a fragment of the cholecystokinin C-terminal octapeptide CCK-8. Studies on the α-chymotrypsin catalyzed coupling reaction between Z-Gly-Trp-R1 and Met-R2 have focused on low water content media, using deposited enzyme on inert supports such as Celite and polyamide. The effect of additives (polar organic solvents), the acyl-donor ester structure, the C-α protecting group of the nucleophile, enzyme loading, and substrate concentration were tested. The best reaction medium found was acetonitrile containing buffer (0.5%, v/v) and triethylamine (0.5%, v/v) using the enzyme deposited on Celite as catalyst (8 mg of α-chymotrypsin/g of Celite). A reaction yield of 81% was obtained with Z-Gly-Trp-OCam as acyl donor, at an initial concentration of 80 mM. The tripeptide synthesis was scaled up to the production of 2 g of pure tripeptide with an overall yield of 71%, including reaction and purification steps. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 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
    Thermodynamic analysis of trinitrotoluene biodegradation and mineralization pathways (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 51 (1996), S. 198-205 
    Details
    ISSN: 0006-3592
    Keywords: trinitrotoluene ; TNT biodegradation ; Gibbs free energy ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biodegradation of 2,4,6-trinitrotoluene (TNT) proceeds through several different metabolic pathways. However, the reaction steps which are considered rate-controlling have not been fully determined. Glycolysis and other biological pathways contain biochemical reactions which are acutely rate-limiting due to enzyme control. These rate-limiting steps also have large negative Gibbs free energy changes. Because xenobiotic compounds such as TNT can be used by biological systems as nitrogen, carbon, and energy sources, it is likely that their degradation pathways also contain acutely rate-limiting steps. Identification of these rate-controlling reactions will enhance and better direct genetic engineering techniques to increase specific enzyme levels.This article identifies likely rate-controlling steps (or sets of steps) in reported TNT biodegradation pathways by estimating the Gibbs free energy change for each step and for the overall pathways. The biological standard Gibbs free energy change of reaction was calculated for each pathway step using a group contribution method specifically tailored for biomolecules. The method was also applied to hypothetical “pathways” constructed to mineralize TNT using several different microorganisms. Pathways steps that have large negative Gibbs free energy changes are postulated to be potentially rate-controlling. The microorganisms which utilize degradation pathways with the largest overall (from TNT to citrate) negatiave Gibbs free energy changes were also determined. Such microorganisms can extract more energy from the starting substrate and are thus assumed to have a competitive advantage over other microorganisms. Results from this modeling-based research are consistent with much experimental work available in the literature. © 1996 John Wiley & Sons, Inc.
    Additional Material: 2 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
    Reactor heterogeneity with Saccharopolyspora erythraea airlift fermentations (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 58 (1998), S. 453-463 
    Details
    ISSN: 0006-3592
    Keywords: Saccharopolyspora erythraea ; airlift reactor ; propeller ; heterogeneity ; cycling dissolved oxygen tension ; hydrodynamics ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bioreactor heterogeneity has been studied in a multiconfigurable pilot-scale airlift reactor (0.25 m3) which created different degrees of heterogeneity. The impact of the two sparger configurations, i.e. in the draft tube or the annulus, in conjunction with a marine propeller fitted at the base of the downcomer, on the physiology of Saccharopolyspora erythraea was studied. Cellular growth, morphology, and productivity were compared between airlift and stirred tank reactors. Dissolved oxygen tension heterogeneity caused by differences in dissolved oxygen tension around the vessel did not affect growth, but the reduction of heterogeneity improved the specific erythromycin production rate and final specific production. Erythromycin production was shown to be proportional to the energy dissipation rate. The enhancement of bubble coalescence with increasing apparent viscosity led to the reduction of the sectional gas holdups and the improvement of liquid mixing. The extent of the changes with increasing apparent viscosity was dependent on the broth morphology, reactor configurations, and operating conditions. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58: 453-463, 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)
  • 10
    Electronic Resource
    Electronic Resource
    Fluid shear effects on suspension cultures of Morinda citrifolia (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 415-425 
    Details
    ISSN: 0006-3592
    Keywords: plant cell suspension culture ; capillary shear loop ; Morinda citrifolia ; shear susceptibility ; morphology ; stirred tank reactor ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The shear susceptibility of cell suspension cultures of the plant cell Morinda citrifolia was investigated by subjecting the cells to the well-defined shear field generated in turbulent flow through a capillary. Suspensions were circulated using a peristaltic pump and average shear stresses between 25 and 350 N m-2 were generated in the capillary test section. Control experiments were performed to assess the possible contribution of the peristaltic pump to the observed cell damage. There was clear evidence of pump-induced damage at the more severe test conditions and all viability measurements were corrected accordingly. Both shake flask suspension cultures (aged between 9 and 15 days) and repeated batch fermentation cultures, grown in a stirred tank reactor (STR) under a variety of controlled agitation conditions, were tested in the capillary shear loop. The cell damage incurred was evaluated in terms of suspension viability, as determined by a dye exclusion technique. Viability loss was found to conform closely to a first-order model in which the rate constant was observed to increase with the imposed shear stress. Furthermore, a linear relationship was identified between the specific death constant and the cumulative energy dissipated. Post-shear morphological measurements showed that the chain length distribution is shifted toward markedly lower values. In comparison with shake flask cultures, repeated batch fermentation cultures exhibited a marked increase in sensitivity to capillary shear. Based upon the determined morphological characteristics, this result is primarily attributable to the increased chain lengths characteristic of the repeated batch cultures. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450506
    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...