摘要:

AbstractTrichoderma virideQM 9414 growth characteristics on glucose were investigated in single stage continuous stirred tank reactor operation and growth parameters μmax,Ks,QO2identified. Multistage stirred tank fermentors in series with the first stage utilizing glucose and the subsequent stages utilizing cellulose yielded results in general agreement with theoretical predictions. Significant increase in enzyme productivity over single stage fermentation was obtained in multistage operation

ISSN:0006-3592    

DOI:10.1002/bit.260170102

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

年代:1975

数据来源: WILEY

摘要:

AbstractAn attempt was made to calculate growth yields of microorganisms on methanol and methane on the basis of known biochemical pathways of C1metabolism. Since 3‐phosphoglycerate is a key intermediate in the assimilation pathways of C1compounds, the calculations were based on the assumption that the synthesis of cell material from C1substrates can be regarded as a two step process. When YATPon 3‐phosphoglycerate was taken as 10.5, a maximal cell yield of organisms of the composition C4H8O2N on methanol was found to be 0.73 g cells/g substrate. For growth on methane a value of 0.91 g cells/g substrate was calculated when a mixed function oxidase was implicated in methane oxidation. These yields were calculated on the basis of the ribulose phosphate pathway of formaldehyde fixation as the major pathway of C1assimilation. Yields calculated on the basis of the serine pathway were on an average 20% lower. The calculations disclosed that for growth on methane, at least forMethylococcus capsulatus, a reversed electron transport system is required when methane is oxidized by a mixed function oxidase. The theoretical cell yields on methanol and methane have been compared with experimentally obtained yields and the validity of the estimations of growth yields on the basis of the present calculations is discus

ISSN:0006-3592    

DOI:10.1002/bit.260170103

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

年代:1975

数据来源: WILEY

摘要:

AbstractA zinc sulfide concentrate was leached microbiologically byThiobacillus ferrooxidansin a continuous stirred tank reactor. A model was developed to predict, the leaching kinetics when the bacterial growth rate was not limited by any substrate other than the zinc concentrate, and it was modified to explain the observed results.Stable steady sates were obtained over a range of dilution rates from 0.0171 to 0.1038 hr−1. Because a solid substrate was used, the specific growth rate of the bacaeria was not a unique function of the subastrate concentration, and conventional contnuous culture theory based on the Monod equation did not apply to this system. The leaching rates and bacterial growth rates were first order in mineral surface area cocentratio

ISSN:0006-3592    

DOI:10.1002/bit.260170104

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe requirements for enzymic cofactor recycling have been investigated in a system employing alcohol and lactate dehydrogenases. The interactions of various combinations of free dehydrogenases or dehydrogenases immobilized either to the same or separate supports, with free NAD, a soluble highmolecular weight derivative of NAD or an insoluble derivative of NAD have been examined.

ISSN:0006-3592    

DOI:10.1002/bit.260170105

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

年代:1975

数据来源: WILEY

摘要:

AbstractA practical method for predicting the dissolved oxygen (DO) profile in a stream receiving biodegradable waste is presented. In this method the BOD (accumulated O2uptake) curve is obtained using an open jug technique. The accumulated O2uptake curve thus developed is employed in numerical integration with the physical reaeration data for the receiving stream to predict the DO profile in the stream. In the present study, the method was examined using 10‐liter open jar reactors to obtain the O2uptake curves, and the receiving stream was a 670‐liter simulated stream apparatus which has been employed in previous studies on stream reaeration. The method was found to provide a fairly good prediction of the actual dissolved oxygen profile observed in the receiving stream. The effect of the reaeration constant, K2)agitation effect(, on the kinetics of O2uptake was also investigated and it was found that increased agitation (higher K2value) caused some increase in the accumulated oxygen uptake (BOD) curve with most of the increase coming after the so‐called “plateau” area in the O2uptake curve, i.e., in the general case, after the low point along the DO

ISSN:0006-3592    

DOI:10.1002/bit.260170106

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

年代:1975

数据来源: WILEY

摘要:

AbstractPectin esterase (E.C. 3.1.1.11) was covalently immobilized to porous glass particles by reaction of the native protein with pendant, benzoyl azide groups of the carrier. Enzyme loading on the carrier was 0.5 unit per ml as measured by pH stat, assay. Decreasing the size of the immobilized enzyme particles by grinding produced a 12‐fold increase in activity suggesting severe internal mass transport restrictions on turnover kinetics, Gross fractionation of the citrus pectin substrate into high and low molecular weight categories and their subsequent use in kinetic characterization shows no effect of molecular weight upon the kinetic behavior of the native enzyme. In contrast the immobilized enzyme displayed a 5‐fold increase in the apparent.Kmfor the high molecular weight fraction relative to that of the low molecular weight fraction. A striking difference exists in the low pH profile of immobilized pectin esterase relative to the native enzyme. Carrier matrix interactions with the polyelectrolyte substrate are invoked to explain this difference. The thermal stability of the immobilized enzyme is relatively low and displays a half‐life of approximately 2 weeks at

ISSN:0006-3592    

DOI:10.1002/bit.260170107

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

年代:1975

数据来源: WILEY

摘要:

AbstractA method of calculating the conversion in Rony's hollow fiber reactor is outlined. It, is assumed that, the kinetics are of Michaelis‐Menten type and that diffusion within the hollow fiber, as well as through its wall, should be taken into account. The normalization of the Thiele modulus suffices to unify the treatment of internal diffusion and the pseudosteady state hypothesis is found to be valid under almost all condition

ISSN:0006-3592    

DOI:10.1002/bit.260170108

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe optimum operating temperature and pH have been determined for a catalyst prepared by the insolubilization of a hepatic microsomal mixed‐function oxidase on glass beads. Temperature is a more significant variable than pH in determining potential catalyst yield (total product/unit catalyst). An operating range of about 25–28°C is optimal with respect to catalyst life at pH 7.6. Like the purified soluble oxidase, the glass bead‐mounted enzyme catalyzes the NADPH‐ and oxygen‐dependent oxidation of a variety of amines, hydrazines, and thioureylenes. The catalyst has been used in a simple slurry reactor to prepare mg quantities ofN‐oxide metabolites of prochlorperazine, guanethidine, and e

ISSN:0006-3592    

DOI:10.1002/bit.260170109

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

年代:1975

数据来源: WILEY

摘要:

AbstractImmobilized glucoamylase, invertase, and β‐galactosidase were prepared by using 2‐hydroxyethyl acrylate and dimethylacrylamide under γ‐ray irradiation. In the case of 2‐hydroxyethyl acrylate, the monomer‐enzyme solution was changed to the gel by irradiation of less than 1.0 Mrad, but it was difficult to eliminate enzyme leakage from the gel. When leakage was eliminated by increased irradiation, the activities of the gels were very low. In the case of dimethylacrylamide, the monomer–enzyme solution was changed to a gel by irradiation of 1.0 Mrad; leakage could be eliminated by irradiation of 2.0 Mrad. This gel possessed very high activity. In the case of acrylic acid‐sodium acrylate, the monomer–enzyme solution could not be changed to a gel. In preparing gels, high concentrations of enzyme protein had a tendency to

ISSN:0006-3592    

DOI:10.1002/bit.260170110

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

年代:1975

数据来源: WILEY

摘要:

AbstractRapid and extensive growth ofBacillus brevisATCC 9999 was obtained in a complex medium containing yeast extract and peptone. Gramicidin S (GS) production in this medium reached 2.5 g/liter and 0.25 g/g dry cell weight. GS synthetase I production was also high in this complex medium. Chemically defined media were also developed for this strain. In a glycerol‐ammonium sulfate‐Tris‐salts medium, the culture grew about 40% as well (rate and extent) as in complex medium. Although GS production was low (0.23 g GS/liter), peak specific activity of GS synthetase I was as high as on complex medium. Nutritional experiments showed that growth was stimulated by glutamine, methionine, proline, arginine, and histidine. Addition of these amino acids almost doubled the rate and extent of growth and GS production on a volumetric basis. However the increase in GS was due merely to the increased cell density; GS synthetase I specific activity was in fact decreased by the supplement. Complex medium is better than defined medium for GS and GS synthetase production due to increased cell density and a slower rate of synthetase disappea

ISSN:0006-3592    

DOI:10.1002/bit.260170111

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

年代:1975

数据来源: WILEY