摘要:

AbstractImmobilizedSporotrichum cellulophilumwith nonwoven materials was cultured continuously by a rotating‐disk fermentor to supply cellulase into the saccharification system. The filter paper activity (5.0) was retained after 696 h under conditions of 250 rpm stirring and 0.014 h−1dilution rate. The product of the culture was supplied continuously to the saccharification reactor and used for the saccharification of bagasse. A glucose solution of ca. 0.9% was obtained continuously from 5% bagasse slurry during 610 h saccharification by this met

ISSN:0006-3592    

DOI:10.1002/bit.260300602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe optimal periodic operation of the biological reactor in which the metabolites belonging to Type I or II in Gaden's classification are produced was investigated from the viewpoint of the multiobjective programming problem. In addition to the productivity of the desired product, its concentration and the conversion of the substrate which have a large influence on the performance of the separation process following the fermentation process were adopted as the objective functions. The growth of cells was assumed to be inhibited both by the substrate and the product, and the Luedeking‐Piret model was employed for the specific production rate. The optimal periodic operation was determined by use of the optimization method due to Miele. It was clarified that the noninferior set for the periodic operation was generally composed of the repeated batch portion and the repeated fed‐batch

ISSN:0006-3592    

DOI:10.1002/bit.260300603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractA two‐parameter deactivation model is proposed to describe the kinetics of activity stabilization for some enzymes. The single‐step unimolecular mechanism exhibits non‐first‐order deactivation kinetics since the final enzyme state,E1is not completely inactivated. The usefulness of the model is demonstrated by applying it to the inactivation of different enzymes. The influence of the concentration of active ester, ionic strength, and pH on the model parameters is examined during the inactivation of electric eel acetylcholinesterase.25In general, inactivators would decrease the level of activity stabilization, α1, and increase the first‐order inactivation rate constant,k1. The effect of protecting agents would be to increase α1and to

ISSN:0006-3592    

DOI:10.1002/bit.260300604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractDetermination of glucose concentrations in fluids frequently requires the application of immobilized glucose oxidase. An accurate description of the immobilized enzyme kinetics is critical for such applications. In this study, the overall rate of reaction of immobilized glucose oxidase is investigated theoretically. A novel steady‐state model based on a ping‐pong kinetic mechanism for glucose oxidase is developed. Numerical studies are used to examine the parameter sensitivity of this model. The enzyme loading, matrix thickness and geometric con figuration are found to have a significant influence on substrate uptake by insolubilized glucose oxidase.Aditionally, this new model is compared with a previously developed model based on an alternative ping‐pong kinetic mechanism. Under steady‐state conditions, no significant difference between the two models is apparent when appropriate kinetic parameters are applied to each of the models. The model developed herein is also compared with models utilizing the simplifying assumption of Michaelis–Mented kinetics for substrate reaction. Numerical studies indicate that under most realizable biological conditions, a model based on ping‐pong kinetics should be applied to accurately describe substrate uptake by immobilized gluc

ISSN:0006-3592    

DOI:10.1002/bit.260300605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe evolutionary performance of up flow reactors are affected by the cell immobilization matrix and the matrix particle size distribution. Higher productivities are obtained using a low‐density brick with a particle size of ca. 400–1400 μm. A medium condition favoring growth quickly leads to large biomass gradients within the reactors and, eventually, reductions in average productivities due to bed plugging. These systems can be accurately modelled using Monod kinetics when dispersion and the biomass gradient are considered. The productivity was apparently not controlled by substrate diffusion in these c

ISSN:0006-3592    

DOI:10.1002/bit.260300606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractOxygen transfer rates and gas holdups were measured in mycelial fermentation broths ofChaetomium cellulolyticumandNeurospora sitophila, each cultured in a 1300‐L pilot‐plant‐scale airlift fermentor. These cultures exhibited highly non‐Newtonian flow behavior coupled with a substantial decrease in oxygen transfer rates. The volumetric mass transfer coefficients in these cultures were found to be 65–70% lower than those in water. The data were compared with the available correlations obtained for simulated fermentation broths. In general, the data forC. cellulolyticumare in satisfactory agreement with the correlations for the model media but the data forN. sitophilaare higher than that predicted by the correlations. Model media based correlations are found to be applicable to the fermentation processes if the culture medium does not possess a high yie

ISSN:0006-3592    

DOI:10.1002/bit.260300607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractQuantification of the degree of acclimation of a mixed culture is demonstrated. An industrial landfill leachate was used as a model mixed substrate. The biodegradable fraction, the specific rate of substrate uptake, and the apparent reaction order were measured. The method of acclimation did not appear to affect the biodegradable fraction. The apparent reaction order is shown to be related to the difference between the rates of uptake of the various leachate components. This difference is defined as thedifferentialin the rate. The effects of a supple mental carbon source and different inocula were investigated. Addition of glucose tends to diminish the differential but also decreases the specific rate of substrate uptake. The outcome of an acclimation procedure is dependent on thequalityof the inoculum; however, a poor inoculum does not preclude an acclimation that yields a superior culture. A normalized rate coefficient is shown to have merit as an indicator of the degree of acclimation. Two microorganisms were isolated,Acinetobacter calcoaceticusvar. Iwoffi andMoraxellasp., that could grow axenically with the leachate as their sole source of carbon. Comparisons are made between pure and mixed cultures with regard to biodegradable fraction, specific rate of substrate uptake, and apparent reaction order.

ISSN:0006-3592    

DOI:10.1002/bit.260300608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractInner filter effects and their interferences in the measurement and interpretation of culture fluorescence are discussed. An approximate light intensity model for a typical open‐ended culture fluorescence measuring device is developed for calculating the fluorescence response of a component of interest in a general three component solution. The model is tested using well de fined synthetic fluorescent systems. The model is then extended for correlating culture fluorescence with cell density and metabolic state of microbial cultures based on a lumping approximation. The extended model has been utilized to derive culture fluorescence parameters of yeast culture at three distinct metabolic state

ISSN:0006-3592    

DOI:10.1002/bit.260300609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260300610

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260300611

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY