摘要:

AbstractRecent experimental results show that the spreading coefficient frequently becomes positive whenCandida lipolyticais cultivated onn‐hexadecane. The effects of oil spreading at the surface of air bubbles in an airlift fermentor are examined using a mathematical model. The distribution of the oil phase with position and among the phases is determined using computer simulation. The simulation results qualitatively explain some of the experimental observations which have been previously reporte

ISSN:0006-3592    

DOI:10.1002/bit.260200402

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe degree of emulsification, measured as surface area of oil generated, was studied. The effect of interfacial tension, volume fraction of oil, and power per unit volume on the Sauter mean diameter of the oil drops was determined in an airlift system with motionless mixers. A mathematical expression to predict the Sauter mean diameter was developed using regression techniques. From this equation another equation, which will predict the surface area of oil in terms of the same variables, was derived. The effects of water air surface tension and power per unit volume on the gas hold‐up were obtained using similar techniques. The results show that the interfacial tension and the surface tension are important variables when hydrocarbon fermentations are carried out in airlift system

ISSN:0006-3592    

DOI:10.1002/bit.260200403

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

年代:1978

数据来源: WILEY

摘要:

AbstractIn order to compare the process economics of making glucose from cellulose, a plant design is presented using acid hydrolysis which can be compared with a published design using enzyme hydrolysis. A common design basis is used; namely, an input capacity of 885 ton/day newsprint with a common technique of cost estimation. The cost of making glucose is in the range of 1.75 to 2.45 cents/lb, depending on the slurry concentration fed to the reactor for the acid hydrolysis. This cost range is less than the published estimate of 5.2 cents/lb for enzymatic hydrolysis.

ISSN:0006-3592    

DOI:10.1002/bit.260200404

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

年代:1978

数据来源: WILEY

摘要:

AbstractA penicillin sensitive enzyme electrode has been used to analyze the concentration of benzylpenicillin in fermentation broth. The electrode response time was in the region of 2 min and the response to penicillin concentration was linear within the range of 1 to 10mM. The buffering capacity of the medium influenced the sensitivity of the electrode. At low buffer capacity the sensitivity of the enzyme electrode to penicillin was very high, but then the sensitivity to small changes in buffer capacity was relatively large. At high buffer capacity the sensitivity to penicillin was reduced and the electrode became less dependent on changes to buffer capacity. Constant calibration curves were repeatedly obtained with the electrode when used for 2 hr daily in a fermentation medium over a six day period. Three methods devised to calibrate the electrode for use in fermentation media were investigated. Methods one and two, based on the relationship between electrode sensitivity and buffer capacity in phosphate buffer and in sterile media, gave rather high penicillin concentration values. The third method based on an internal standard was the most satisfactory.

ISSN:0006-3592    

DOI:10.1002/bit.260200405

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe fast enzymatic hydrolysis ofD,L‐phenylalanine methylester (DLE) toL‐phenylalanine (LA) andD‐phenylalanine methylester (DE) with immobilized α‐chymotrypsin was chosen as a model reaction. Under the experimental conditions applied in the present investigations the pore diffusion is the rate‐limiting step of this reaction owing to the pH gradient in the particles. The effectiveness of the catalyst is experimentally determined as a function of the substrate concentration based on measurements of the enzyme protein content of native and immobilized enzyme. The proteolytic reaction is theoretically treated by also using a pore diffusion model which takes into account the concentration gradients of substrate and product, pH‐ and enzyme activity profiles, as well as the change of buffer capacity of the solute in the catalyst particles. The model parameters were experimentally determined for the investigated system. It can be shown that conditions are possible for which the effectiveness of the catalyst e

ISSN:0006-3592    

DOI:10.1002/bit.260200406

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

年代:1978

数据来源: WILEY

摘要:

AbstractCulture broths of cellulolytic fungi were used together with commercial amylases to enhance the saccharification of cassava starch slurry. It was found that the addition of appropriate concentration of the cellulasesTrichoderma virideand a soil isolatedBasidiomycete, increased both the rate of sugar formation and the degree of solubilization, and decreased the viscosity of the hydrolyzates. Owing to the improvement of the rheological properties of the must, and the additional sugar produced, an increased ethanol yield would be expected from the alcoholic fermentation of this hydrolyzate.

ISSN:0006-3592    

DOI:10.1002/bit.260200407

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe effects of two grinding methods, hammer milling and defibrizing by disk refining, on the fermentability of ryegrass straw were investigated. Disk refined or defibrized straw produced more sugar than hammer milled straw. Release of sugar was especially pronounced when H2SO4was added to the straw during the defibrizing process.In vitrorumen digestibility was significantly higher (P<0.1) for defibrized than for hammer milled straw. With semisolid culture the level of yeast growth was about three times as high on the defibrized as on hammer milled straw. A scanning electron micrograph revealed that defibrizing removed the waxy surface of the straw as well as separating fiber bundles, so that the surface area of the exposed fiber structure was increased.

ISSN:0006-3592    

DOI:10.1002/bit.260200408

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe exocellularDD‐carboxypeptidase–transpeptidase thatStreptomycesR61 excretes during growth has been produced in large fermentation units of 15 m3total capacity. The yield from 15,000 liter culture filtrate was 1.080 g purified enzyme (92% purity) with a total recovery of 29% and at least a 2000‐fold increased specific act

ISSN:0006-3592    

DOI:10.1002/bit.260200409

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

年代:1978

数据来源: WILEY

摘要:

AbstractCombining acid cottage cheese whey and the lime–sulfide effluent from tannery unhairing processes spontaneously coprecipitates the whey proteins with the large peptides and proteins of the tannery waste. The floculation of the denatured protein material also carries down the hide pigments, excess lime, and the casein fines from the whey. The clear supernatant contains lactose, sulfur in various states of oxidation, free amino acids, peptides, and ammonium salts, but no detectable macromolecular proteins. The recovered solid products, which contain more than 20% of the original nitrogen, appear to have a good balance of essential amino acids although actual composition varies with the composition of the raw wastes. Feed supplements may possibly by obtained by this method from two presently wasted industrial effluent

ISSN:0006-3592    

DOI:10.1002/bit.260200410

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

年代:1978

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260200411

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

年代:1978

数据来源: WILEY