摘要:

AbstractCandida utiliswas grown in batch culture with and without oxygen control. The concentrations of A‐, B‐, and C‐type cytochromes were found to vary with the initial glucose concentration, with the dissolved oxygen concentration, and with time. A‐type was the most sensitive. After glucose was essentially exhausted, the yeast catabolized ethanol, if it had been growing in a relatively low initial glucose concentration, or non‐glucose carbohydrate, including some of that previously accumulated within the cell, if it had been growing in a high initial glucose concentration. This difference in metabolic pattern could explain why cytochrome derepression was initiated soon after glucose uptake ceased only if initial glucose had been relatively low. The effects of glucose and dissolved oxygen concentrations on yeast cytochromes and respiratory activity are

ISSN:0006-3592    

DOI:10.1002/bit.260130202

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

年代:1971

数据来源: WILEY

摘要:

AbstractUltrafiltration has been used with increasing frequency in recent years in biological laboratories for concentration, separation or purification of biological material. No data have been available on the comparison of the characteristics of Ultrafiltration systems currently in use. This study compares the filtration characteristics of four systems using commercially available membranes on suspensions and solutions: suspension of protein micelles (casein), cell debris (E. coli) and catalase solution. None of the four systems considered is found to be generally superior for all the suspensions and solutions. Vibration systems were most effective when relatively large particles were involved, while laminar flow recycling systems with high wall shear rates were best for dilute suspensions and proteins in solution. It was found that shearing inactivates enzymes in both recycle and vibration systems. It was also observed that vibration actually reduces flux in dilute solutions.

ISSN:0006-3592    

DOI:10.1002/bit.260130203

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

年代:1971

数据来源: WILEY

摘要:

AbstractA process for the bacterial oxidation of isobutyric acid toL(+) β‐hydroxyisobutyric acid has been developed. The strain ofPseudomonas putida(ATCC 21244) used in this fermentation was isolated from local soil. The process was carried out in a 15‐liter fermentor over a period of 70 hr and producedL(+) β‐hydroxyisobutyric acid in conversions as high as 48%. Hydroxylation of the methyl group of isobutyric acid has special interest because it is difficult to perform chemically. The useful chemical syntheses of β‐hydroxyisobutyric acid available at present do not start with isobutyric acid and are not ster

ISSN:0006-3592    

DOI:10.1002/bit.260130204

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

年代:1971

数据来源: WILEY

摘要:

AbstractGrowth rates ofCandida tropicaliswere studied in two different fermentors. One was the ordinary shaker flask containing both the aqueous culture medium and liquid hydrocarbons. The other was a specially designed rotating disk‐type fermentor containing only the aqueous culture medium, into which vapors of n‐paraffins from C6to C18were supplied continuously without forming the liquid hydrocarbon phase. The specific growth rates ofCandida tropicalisin the rotating disk fermentor, under such conditions that supply of hydrocarbon vapor was sufficient, showed good agreement with those in the shaker flask. This seems to indicate that hydrocarbon uptake byCandida tropicalsby direct contact with liquid hydrocarbon is negligi

ISSN:0006-3592    

DOI:10.1002/bit.260130205

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

年代:1971

数据来源: WILEY

摘要:

AbstractA decoyinine resistant, KY 13501, isolated after nitrosoguanidine treatment fromBrevibacterium ammoniagenesATCC 6872 converted 5′XMP added in fermentation media to guanine derivatives and accumulated them in the media. The converted substances were identified as guanine, 5′GMP, 5′GDP, and 5′GTP. The conditions for the conversion were examined and the following points were clarified. (1) Very low concentration of manganese ion (Mn2+) showed profound effects on the conversion and the excessive amounts of the ion severely repressed the conversion. (2) Under limitation of Mn2+, 5′XMP was converted most efficiently when added at inoculation time. (3) The inhibition of the conversion by excessive amount of Mn2+was completely released by addition of a surface activating agent, polyoxyethylene stearylamine. (4) For the conversion, it was essential to maintain pH of the media at 7.5 to 8.0 and supply amm

ISSN:0006-3592    

DOI:10.1002/bit.260130206

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe effects of inoculum size, dispersed phase volume and substrate concentration on the batch growth ofCandida lipolyticaare investigated in a model system composed ofn‐hexadecane dissolved in dewaxed gas oil. Tabular values and parameters are presented for 16 different experiments. All of the batch growth curves exhibited a linear growth region with the length of the region ranging from 1.5 to 9.5 hours. The rate of linear growth varied both with change in dispersed phase volume and initial dispersed phase substrate concentration. A qualitative analysis of the results is presented and possible explanations for the observed linear growth rates are discusse

ISSN:0006-3592    

DOI:10.1002/bit.260130207

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe interaction between male‐specific RNA phages and bacterial cells as well as the complete life cycle of RNA phages in the host cells are complicated phenomena. In this study, a mathematical model is proposed to describe the kinetics of RNA phage production in batch culture. The model consists of several important considerations: (1) adsorption and desorption of phages on cell pili, (2) injection and transport of viral RNA, (3) viral protein synthesis, (4) phage maturation, and (5) cell lysis.Experimental data of MS2 RNA phage production inE. coliC 300o bacteria culture were used to evaiuate the model parameters. Reasonably good fit was obtained between the model and one set of data. However, simulation study based on the estimated parameter values revealed a discrepancy between experimental observation and model prediction. It seems that variation both inF‐piliation and in the competence of cells to be infected by phages through different phasae of growth must be taken into account in order to make the model use

ISSN:0006-3592    

DOI:10.1002/bit.260130208

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

年代:1971

数据来源: WILEY

摘要:

AbstractOxygen transfer coefficients were evaluated for a 14‐liter stirred tank fermentor equipped with an oxygen probe, employing elemental copper adsorbed on a weakly basic anion‐exchange resin as a solid phase oxygen acceptor. The use of a solid phase oxygen acceptor allowed evaluation of mass transfer resistances associated with the solid phase, and the effect of an oxygen adsorbing solid phase on the overall oxygen transport system, portions of the oxygen transfer process that are neglected by the conventional sulfite oxidation method commonly employed. It was concluded from the data obtained that a transport pathway involving transfer of oxygen to particles present near the air‐water interface was a significant oxygen transport pathway for the system studied. Oxygen probe measurements performed on the bulk liquid did not recognize this pathway, suggesting that data taken on biological systems by use of techniques involving oxygen concentration measurements in the bulk liquid may not give the true oxygen absorbing capacity of a s

ISSN:0006-3592    

DOI:10.1002/bit.260130209

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe mode of ethanol action on both the steady‐state and the dynamic properties ofK. aerogeneswas investigated using a nitrogen‐limited chemostat. Reduction in the maximum growth rate (μm) suggests that noncompetitive enzyme inhibition could occur, but Lineweaver–Burk analysis showed the inhibition to be more complex. A consistent mechanism of inhibition was established for 0–3% v/v ethanol. Warburg manometric experiments indicated that inhibition occurred in pathways located in the intact cell wall. Frequency response analysis, using sinusoidal variations in the dilution rate showed that ethanol increased the time constant of the metabolic parameter,QAC. The system was stable in the presence of ethanol and showed no evidence of oscillations following a dis

ISSN:0006-3592    

DOI:10.1002/bit.260130210

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

年代:1971

数据来源: WILEY

摘要:

AbstractPartially purified glucoamylase fromAspergillus awamoriNRRL 3112 was immobilized on diethylaminoethyl cellulose in the presence of low ionic‐strength acetate buffers at pH 4.2. The active enzyme–cellulose complex was used to convert starch substrates continuously to glucose in stirred reactors. Substrate concentrations as high as 30% could be quantitatively converted to glucose at a rate of more than 25 mg/min/liter at 55°C for periods of 3 to 4 weeks in a 4‐liter reactor. Shutdowns were due to mechanical problems and not to loss of enzymes, which could be recovered with no appreciable loss of specific activity. Transfer products, such as isomaltose and panose, were present in immobilized enzyme‐produced syrups but to no greater degree than in soluble glucoamylase digests o

ISSN:0006-3592    

DOI:10.1002/bit.260130211

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

年代:1971

数据来源: WILEY