摘要:

AbstractA fermentor was designed and constructed for study of the physical, microbiological, and chemical changes that occur during the sauerkraut fermentation. The fermentor has some essential features that include restriction in volume of the sauerkraut bed, construction of clear plastic to permit visual determination of liquid‐level changes as a result of gas entrapment within the sauerkraut bed, and a gas‐lift device for use in nitrogen purging of the fermenting brine. Fermentations exhibited two distinct stages, the first one gaseous and the second non‐gaseous. The gaseous stage was characterized by rapid CO2and acid production due to growth by hetero‐fermentative lactic acid bacteria with resultant gas entrapment within the sauerkraut bed and a rise in liquid level. Also, rapid disappearance of fructose and rapid appearance of mannitol occurred during this stage. The nongaseous stage was characterized by growth of homo‐fermentative lactic acid bacteria with little or no CO2production and a gradual increase in lactic acid until all fermentable sugars were metabolized. Nitrogen purging appeared to offer several potential advantages, including a means for brine circulation, removal of CO2from the brine, and anaerobiosis to ensure retention of ascorbic acid, desirable color, and other oxygen‐sensitive traits in

ISSN:0006-3592    

DOI:10.1002/bit.260310302

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe model of a continuous‐stirred tank biochemical reactor was developed in which the instant uptake rate of substrate was used. The solutions of the model found for the oxidation of phenol byPseudomonas putidafitted the experimental data better than the results obtained from the models cited in the literature. The model enables control of the culture parameters so that the unwanted washout of the biomass from the bioreactor can be avoided. A review of the models cited in the literature is also presente

ISSN:0006-3592    

DOI:10.1002/bit.260310303

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

年代:1988

数据来源: WILEY

摘要:

AbstractCellulose materials can readily be degraded into cellobiose and glucose by hydrolysis of the enzymes cellulase and β‐glucosidase in aqueous media. Product inhibition does, however, retard the reaction rate and reduce productivity. This may be avoided by carrying out the degradation of cellulose in an aqueous two‐phase system, which permits the enzymes and the substrate to be partitioned to one phase and the products to be extracted into a second phase. In addition, two‐phase systems also allow recycling of the enzymes. Here, three models previously developed for “one‐phase” enzymic degradation are compared to data from enzymic degradation in an aqueous two‐phase system. The models tested agreed relatively well with batch experiments during a period of 200 h. For one of the models tested, continuous degradation also gave accu

ISSN:0006-3592    

DOI:10.1002/bit.260310304

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

年代:1988

数据来源: WILEY

摘要:

AbstractPorcine pancreatic andChromobacterium viscosumlipases catalyze transesterification reactions between a number of sugar alcohols and various plant and animal oils in dry pyridine. The products of this process have been identified as primary monoesters of sugar alcohols and fatty acids. These enzymatically prepared sugar alcohol esters have been found to be excellent surfactants in terms of their ability to reduce interfacial and surface tensions and to stabilize emulsions.

ISSN:0006-3592    

DOI:10.1002/bit.260310305

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

年代:1988

数据来源: WILEY

摘要:

AbstractIn order to study the single‐cell proteins and cellulase production, fungal degradation of α‐cellulose was tested. Photochemical pretreatment of α‐cellulose at λ>254 nm increases by over 100% the cellulase production byChrysonilia sitophila(TFB strain). This is reflected in a larger production of soluble proteins in the filtrate with higher cellulase activity when compared with unirradiated cellulose. Single‐cell protein production (insoluble proteins) was also improved after preirradiation of cellulose or even on rice hull as the only carbon source after inoculation with the spore ofC. sitophila. This pretreatment is a valuable method for increasing the digestibility of lignocellulosic

ISSN:0006-3592    

DOI:10.1002/bit.260310306

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe method of chemical aggregation of enzymes has the advantage of yielding an immobilized enzyme preparation wherein reactor volume can be significantly reduced because of the absence of an inert carrier. A coaggregate of trypsin and chymotrypsin formed by extensive cross‐linking with glutaraldehyde is described. A significant property of this aggregate is the reduced autolysis of the trypsin component of the coaggregat

ISSN:0006-3592    

DOI:10.1002/bit.260310307

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

年代:1988

数据来源: WILEY

摘要:

AbstractOptimal control theory was applied to the process of batch beer fermentation. The performance functional considered was a weighted sum of maximum ethanol production and minimum time. Calculations were based on the model of Engasser et al. modified to include temperature effects. Model parameters were determined from isothermal batch fermentations. The fermentor cooling duty was the single available control. Temperature state variable constraints as well as control variable constraints were considered. The optimal control law is shown to be bang‐bang control with the existence of a singular arc corresponding to isothermal operation at the maximum temperature constraint. An iterative algorithm is presented for computing appropriate switching times using a penalty‐function‐augmented performance funct

ISSN:0006-3592    

DOI:10.1002/bit.260310308

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

年代:1988

数据来源: WILEY

摘要:

AbstractA mathematical model is presented for a microporous hollow‐fiber membrane extractive fermentor (HFEF). The model is based on the continuous flow of the aqueous nutrient phase and cells through the shell space of the fermentor where the fermentation reaction occurs. The product diffuses from the shell space through the hollow‐fiber membrane where it is continuously removed by solvent flowing concurrently through the fiber lumen. Results for ethanol production show that the HFEF has a volumetric productivity significantly higher than that possible using conventional methods. The model predicts the existence of an optimum volume fraction of hollow fibers in the fermentor that maximizes the total volumetric productivity. This optimum is the result of a classic trade‐off between the volume fraction of the fermentor required for fermentation and that required for efficient removal of the ethanol product to minimize product inhib

ISSN:0006-3592    

DOI:10.1002/bit.260310309

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

年代:1988

数据来源: WILEY

摘要:

AbstractA model is developed and used to predict the dynamic behavior of the elution stage of biospecific adsorption (affinity chromatography) in a finite bath. Both nonselective and selective elution of monovalent adsorbates is considered. The model expressions account for film and pore diffusion resistances for the adsorbate(s) and the eluent, and various rate expressions for the desorption of the adsorbate from the adsorbate–ligand complex are constructed and studied. The results indicate that the duration of the elution stage depends significantly on the Sherwood number of the adsorbate and the rate of the interaction step between the ligand and the adsorbate relative to the diffusion of the adsorbate in the pore during elution. In nonselective elution, when the value of the effective pore diffusivity of the eluent is significantly larger than that of the adsorbate, the results suggest that it would be advantageous to use an initial eluent concentration in the finite bath that is only slightly higher than the critical eluent concentration in order to minimize the risk of product and ligand damage. In selective elution the amount of adsorbate recovered in the elution stage is greatly influenced by the initial concentration of the eluent and the equilibrium dissociation constants of the adsorbate–ligand and adsorbate–eluent comp

ISSN:0006-3592    

DOI:10.1002/bit.260310310

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

年代:1988

数据来源: WILEY

摘要:

AbstractBiosensors with animal and microbial cells immobilized close to the tip of a membrane electrode have been developed for chemical and drug testing. Our experimental results show that biosensors can be used for drug screening and to provide useful information about various cell‐chemical interactions. A computer aided analysis (CAA) software package is being developed here using the biosensor for various screening purposes. This software package enables us to use a computer to analyze the biosensor dynamic responses. Computer simulation and parameter estimation techniques are used to select the best model and to describe the biochemical and pharmacologic effects of various chemicals and drugs on different cell line

ISSN:0006-3592    

DOI:10.1002/bit.260310311

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

年代:1988

数据来源: WILEY