摘要:

AbstractFactors influencing foam concentration of proteins are studied. Projecting practical application of the results, the possibilities for obtaining good enrichment ratio are studied. The dependencies of enrichment ratio and albumin concentration in the foam on the initial solution concentration and expansion factor are investigated. Using a method of application of pressure difference in the Plateau‐Gibbs borders of the foam, stabilized by albumin and lysozyme, comparatively high enrichment ratio of the proteins is obtained. The method is applicable for any protein foams and is more effective for more stable foams. The enrichment ratio of albumin significantly depends on the parameters and properties of the foam (dispersion, expansion factor, stability, etc). and also on the initial concentration of the solution. The protein concentration in the foam and the foam dispersion depend in a different way on the initial concentration by the creation of pressure difference in the foam and theRf/C0dependence shows a maximum. The latter indicates the existence of an optimum of the initial protein concentration with respect to the efficiency of the foam concentration and the foam separation of proteins from solution

ISSN:0006-3592    

DOI:10.1002/bit.260230402

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

年代:1981

数据来源: WILEY

摘要:

AbstractNickel‐NiO‐BSA‐chymotrypsin has been used to hydrolyze casein in both batch and continuous stirred tank reactors. The kinetics of hydrolysis in both types of reactor were considered. Some operational problems encountered using fine powder catalysts in batch stirred tank reactors are discussed. High gradient magnetic separation was found to be a powerful catalysts retention method for magnetic support particles, particularly when using a ferromagnetic collection matrix. Nickel particles of diameter 3–7 μm were easily separated from water at a processing velocity of 39 mm/sec. Nickel powder and precipitated Fe3O4were also separated satisfactorily using a rotating drum magnetic s

ISSN:0006-3592    

DOI:10.1002/bit.260230403

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

年代:1981

数据来源: WILEY

摘要:

AbstractRate expression for enzyme poisoning which are consistent with a Michaelis‐Menten main reaction are used to analyze the performance of a fixed bed reactor containing immobilized enzyme. When enzyme deactivation results from the irreversible bonding of a product molecule to an existing substrate‐enzyme complex, it is shown that minimum enzyme activity can occur in theinteriorof the bed, well away from the ends. This suggests that bed sectioning techniques may enable direct evaluation of fundamental poisoning mechani

ISSN:0006-3592    

DOI:10.1002/bit.260230404

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe use of calcium alginate gels for the “Solids Separation” techniques was demonstrated by entrapment of a yeast extract in calcium alginate pellets and the study of the release of alcohol dehydrogenase and NADH into a dilute calcium chloride solution. The use of calcium alginate gels for a “Diffusional Chromatography” technique was demonstrated in a model system by a fractionation of NAD and hemoglobin release following their entrapment in calcium alginate pellets. The advantages of these techniques and their potentials are di

ISSN:0006-3592    

DOI:10.1002/bit.260230405

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

年代:1981

数据来源: WILEY

摘要:

AbstractThere is now growing evidence that the production of many secondary metabolic by microorganisms is subjected to carbon‐catabolite regulation. Even though the exact mode of this regulation is not yet clear, an engineering analysis of the production process is still possible based upon a suitable hypothesis. By way of simulation of penicillin fermentation data obtained from the literature, a mechanistic model involving a substrate inhibition kinetics of product formation has been verified in this paper. Such a model has been found successful not only in predicting simple sugar‐feeding strategy, but also a complicated computer guided strategy based upon controlling biomass growth rates in the tropo and idiophases. Using this model, for strategies for sugar feeding into penicillin fermentation have been investigated. These results show that similar penicillin productivities can be obtained using any of these strategies provided fermentations are carried out under optimal conditions corresponding to the strategy chosen. Effect of maximum oxygen transfer capacity of the fermentor under the conditions of fungal growth has been incorporated using an upper limit of biomass concentration on achievement of which the fermentations must be stopped due to serious oxygen limitations. Results of model simulations with such limits throw light upon the way in which different fermentors may behave with respect to product format

ISSN:0006-3592    

DOI:10.1002/bit.260230406

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe present paper presents a generalized treatment of the principles of elemental and enthalpy balances which are applied to aerobic fermentation processes. It is shown that strict relations do exist between the various yield factors of biomass or product on substrate, oxygen, carbon dioxide, and between the various maintenance coefficients. These relations are confirmed from the existing body of literature data on yield and maintenance coefficients. Another consequences of the application of elemental balances is the existence of limits for the maximum biomass yield on substrate and oxygen, which depend on the degree of reduction of the substrates with different degree of reduction. It appears from this model that substrates with a high degree of reduction are C limited and substrates with a low degree of reduction are energy limited. Finally the effects of temperature on yield and maintenance coefficients are analyzed from the existing body of literature data. It can be concluded that the maintenance coefficients follow an Arrhenius type of relationship and that yield is temperature independent. The literature data seem to indicate that a degree of reduction of about 4 is optimal for the carbon and energy needs for biomass formation.

ISSN:0006-3592    

DOI:10.1002/bit.260230407

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe disruption ofCandida utiliscells in suspensions subjected to different types of stress was investigated. Stresses caused by impingement of a high velocity jet of suspended cells against a stationary surface were found to be significantly more effective for disruption than either shear or normal stresses. The fraction of cells disrupted by impingement is a first order function of the number of passes through the disruptor and, over a prescribed range of operating pressures, is a power function of pressure. These results indicate that impingement is the predominant mechanism causing cells disruption in high pressure flow devices such as Manton–Gaulin homogenizers. The impingement results suggest that cells grown in cyclic batch culture are easier to disrupt than cells grown at a lower specific growth rate in continuous culture. In addition to determining the fraction of cells disrupted, the release of invertase activity was determined for the impingement experiments. The fraction of total invertase activity released was found to be somewhat greater than the fraction of cells disrupte

ISSN:0006-3592    

DOI:10.1002/bit.260230408

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

年代:1981

数据来源: WILEY

摘要:

AbstractSlime‐covered rocks and samples of process waters from two trickling filters for treatment of municipal wastes were brought to the laboratory for probing with microelectrodes to determine dissolved oxygen (DO). Slime thickness was 0.4–1.5 mm. Flow rate of medium over the slime had a minor effect on slime respiration, but pH 5 or below was strongly inhibitory. Increasing temperature showed lower oxygen concentration throughout a slime, although 27°C had results little different from those at 22°C. Medium concentration had a profound effect on oxygen concentration profiles, and either oxygen‐limited or substrate limited respiration could be demonstrated. Illumination of slimes from the top of the trickling filter developed oxygen supersaturation because oxygen from photosynthesis could not diffuse away

ISSN:0006-3592    

DOI:10.1002/bit.260230409

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

年代:1981

数据来源: WILEY

摘要:

AbstractEnergetic yields associated with microbial growth on hydrocarbons are investigated and compared with values for other organic substrates. Both cell growth and extracellular product formation are investigated. Both carbon and energy limitations are considered in estimating theoretical yields. Carbon, available electron, and ATP balances are used in the theoretical analysis. The results indicate that the availability of carbon may limit growth and product formation.

ISSN:0006-3592    

DOI:10.1002/bit.260230410

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

年代:1981

数据来源: WILEY

摘要:

AbstractAn approximate analytical solution which describes the deactivation of catalase immobilized on porous supports is provided. Catalase was chosen as an example of an enzyme which undergoes parallel poisoning. The solution incorporates the effects of pore diffusion and of the parallel poisoning. The solution incorporates the effects of pore diffusion and of the parallel poisoning of catalase by its substrate hydrogen peroxide into a time dependent effectiveness factor which can then be inserted into the appropriate reactor equations. The model was tested by measuring experimentally the deactivation of immobilized catalase in both a packed bed reactor and a continuous stirred basket reactor and was found to be very satisfactory at inlet substrate concentrations of less than 0.02M. Values of the deactivation rate constant obtained by regression analysis were independent of particle type and size and reactor description indicating that they were in fact inherent characteristics of the immobilized enzymes which are immobilized on supports and which undergo substrate or parallel poisoning.

ISSN:0006-3592    

DOI:10.1002/bit.260230411

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

年代:1981

数据来源: WILEY