摘要:

AbstractA theoretical approach to the prediction of stripping or accumulation of minor components in solution with water by a sparged stream of dry air bubbles is developed and tested experimentally for two model systems, containing 1 mole‐% respectively, of ethanol, to represent situations where the minor component is more volatile than water, and of acetic acid, to represent the reverse. Close agreement between theory and practice is achieved in the former case, where an overall reduction in the liquid phase concentration of the minor component occurs, while in the latter, where overall accumulation occurs, there is some discrepancy. Considerations for an extension of the study are include

ISSN:0006-3592    

DOI:10.1002/bit.260070202

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe effect of operating temperature upon relative stripping of a two component (ethanol–water) mixture by dry air, with the aid of a previously derived equation,1is considered. The variations encountered in the relative humidity of air sparged to fermentors are discussed. A general equation is developed for the stripping of a more volatile component from a solution in water by wet air. The theoretical results derived from this equation are tested experimentally at one particular level of prehumidity of the air sparged to an ethanol–water sys

ISSN:0006-3592    

DOI:10.1002/bit.260070203

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe kinetics of the gluconic acid fermentation have been studied at pH 5.8Pseudomonas ovalisB‐1486 was used as the fermenting organism.D‐Gluconolactone was found as an intermediate in the fermentation and accumulated at times in large amounts. When this occurred, hydrolysis of the lactone was found to be the rate limiting reaction. This can be, under certain conditions, a poor fermentation in which to study oxygen transfer limiting conditions. Further, it is impossible to relate batch and continuous kinetic data for this fermentation unless the lactone hydrolysis reaction is taken into acco

ISSN:0006-3592    

DOI:10.1002/bit.260070204

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

年代:1965

数据来源: WILEY

摘要:

AbstractIn order to find effective methods to isolate microorganisms that excrete large amounts of amino acids, a number of mutants ofEscherichia coliATCC 4157 were prepared and characterized. The majority were isolated for resistance to amino acid analogs. The penicillin method was also employed to select potential producer strains devoid of a biosynthetic enzyme in one case and a catabolic enzyme (tryptophanase) in another. Both of these enzymes were suspected of reducing the yield of an excerted amino acid. The identification of amino acid excreting colonies was aided by the use of pigmented auxotrophic test bacteria.Amino acid analog resistance was frequently found to increase amino acid production. In particular, excretion of valine and glutamic acid could be achieved with comparative ease. Conditions of culture were of extreme importance for the amount and kind of amino acid produced. Under certain conditions a norvaline‐resistant strain and even better a leucine‐requiring derivative of it excreted more than 2 mg./ml. of valine into the culture medium. The acetolactate‐forming enzyme of this strain was not repressible by leucine in contrast to the same enzyme in the wild type. Reversal of the growth inhibitory effects of amino acid analogs by amino acids was studied on agar plates. This method gave too complex results to be a simple guide in the selection of analogs suitable for the isolation of a particular type of production m

ISSN:0006-3592    

DOI:10.1002/bit.260070205

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe addition of potassium ferrocyanide to the molasses substrate (mash) used in the citric acid fermentation had little or no effect on the total carbon, nitrogen, or phosphorus content of the substrate but reduced the ash content by 1–4% depending on the type and crop year of molasses. Eighteen of the 21 metals identified in beet molasses by spectrographic analysis were precipitated in part by the treatment. The metals known to interfere with citric acid production, particularly manganese and iron, were those most efficiently precipitated. At mash temperatures of 80°C. and approximately 100°C., precipitation was completed within 15 min. after ferrocyanide addition and the reductions in the soluble mineral content in each case were similar. At 25°C. the precipitation reactions occurred but required more than 50 hr. to complete. Significantly more total mineral and more iron, calcium, and copper were precipitated at pHs 4 and 6 than at pH 8; manganese precipitation, however, was not affected by these pH cha

ISSN:0006-3592    

DOI:10.1002/bit.260070206

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

年代:1965

数据来源: WILEY

摘要:

AbstractContinuous cultures of some heterotrophicSpirilli(Sp. serpens, Sp. curvatum, Sp. sp.) exhibit threshold concentrations of lactate, the growth limiting carbon and energy source, around 15 mg./l. This value corresponds to a threshold population density of 0.92 mg. dry weight/l. at a dilution rate ofD= 0.185 hr.−1(= 0.5 maximum growth rate). The minimum population density, which is regarded as equivalent to the starter population in batch culture, was dependent on the growth rate and the redox potential. The existence of minimum populations and the pronounced effect of population density on growth at low nutrient levels seem to be widespread phenomena closely related to growth under suboptimal condition

ISSN:0006-3592    

DOI:10.1002/bit.260070207

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

年代:1965

数据来源: WILEY

摘要:

AbstractWith a view to preparing substitutes for liver or other animal protein hydrolysates used in the treatment of protein malnutrition, a process has been developed based on sesame and mustard cakes as the starting materials. The laboratory process has been successfully scaled up to pilot plant production to compute tentative costing schedule. Essentially the process consists in defatting the cake, isolating the protein by peptization and isoelectric precipitation, enzymatically digesting the protein isolate by papain, and concentrating the digest under reduced pressure. The final product is a light brown fluffy powder, rich in almost all the essential amino acids. Growth experiments with rats have indicated that the product is comparable to commercial casein although supplementation with lysine could further enhance its biological value.

ISSN:0006-3592    

DOI:10.1002/bit.260070208

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

年代:1965

数据来源: WILEY

摘要:

AbstractLarge cultures of microscopic, unicellular algae have been proposed as a means of maintaining a life‐supporting atmosphere in a closed, manned system. To achieve vigorous growth of the algal culture it is necessary to subject individual algae alternately to short periods of high intensity light and darkness. One of the means suggested for obtaining a favorable light–dark sequence for photosynthesis is to cause turbulence in a closed channel on which light is incident. Since light is rapidly attenuated in a dense suspension, there will be illuminated regions adjacent to the channel walls and a dark central core. The random motions of turbulence normal to the direction of flow would move the algae alternately from the illuminated regions to the dark region and back again. This paper indicates a method for analyzing the motion of algae into and out of the illuminated region of a channel formed by flat, parallel, transparent plates, with light incident on the plates. Matching of a probability model with a diffusion model makes it possible to estimate the light–dark sequence which could be achieved by turbulence. The results indicate that favorable sequences by this mechanism are unl

ISSN:0006-3592    

DOI:10.1002/bit.260070209

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

年代:1965

数据来源: WILEY

摘要:

AbstractPseudomonas aeruginosaNCTC 5940 was grown in an aerated mineral salts medium with pure octadecane as sole carbon source, both in batch and continuous culture experiments. Carbon and nitrogen balances were made under different conditions. It was found that the only significant products were fresh cell tissue and carbon dioxide, although traces of several fatty acids were detected.

ISSN:0006-3592    

DOI:10.1002/bit.260070210

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

年代:1965

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260070211

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

年代:1965

数据来源: WILEY