摘要:

AbstractThe isolation and properties of strains ofEscherichia colicarrying mutations affecting either the low affinity transport for gluconate (gene gntU) or the thermoresistant gluconokinase (gene gntK) are described. A lesion of each type was genetically characterized by transduction experiments. Both mutations mapped in the asd region, and the order was malA‐glpD‐asd‐gntU‐gntK, with the last two markers at about min 75.78 and 75.86 on the map, respectively. Mutations altering specifically gntU have not been previously r

ISSN:0233-111X    

DOI:10.1002/jobm.3620340602

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe cellulase complex ofS. albaduncuswas found to undergo catabolite repression in the presence of glycerol accompanied by a decrease in the pH of the medium. The results of the experiments conducted at two different initial pH of the medium suggested that pH effect as well as proteases were involved in the inactivation of glucanases (exoglucanase and endoglucanase) whereas β‐glucosidase inactivation was solely due to ‘pH effect’. It was also apparent that pH change followed by the addition of glycerol caused alterations in protease activities as well as pattern of their prod

ISSN:0233-111X    

DOI:10.1002/jobm.3620340603

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractYeasts growing in “Tokaj Aszu” wine and in “Aszu essence” were isolated and characterised. They proved to be physiological races ofSaccharomyces cerevislaeand showed high osmotolerance, which was an inherited feature rather than the result of adaptation. No correlations were found between the osmotolerance and the ethanol tolerance or the cell size and morphology. Yeasts in “Aszu essence” are usually undesirable contaminants that impair the quality of the essence. The isolate characterized in this work exhibited physiological parameters very similar to those of the “Tokaj Aszu” strain, which make it a potent competitor of other yeasts in Aszu fermentation. However, the high termo sensitivity of its cells offers a possibility to eliminate t

ISSN:0233-111X    

DOI:10.1002/jobm.3620340604

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe role of the lipid bilayer and the peptidoglycan of the mycobacterial cell wall in the permeation of β‐sitosterol into the cell and its transformation to androst‐1‐ene‐3,17‐dione (AD) and androsta‐1,4‐diene‐3,17‐dione (ADD) was studied. Specific inhibitors were used at concentrations affecting the biosynthesis of the assumed target structures, but causing only partial cell growth inhibition or exerting no effect on growth.m‐Fluorophenylalanine and dl‐norleucine which are known to disorganize the biosynthesis of amphipatic components of the outer layer of the lipid bilayer, used at concentrations 250 μg/ml and 400 μg/ml, respectively, increased the formation rate of AD + ADD from 0.3 (control) to 0.7 and 0.8 mg products/g dry weight/h. The disorganization of the underlying mycolyl‐arabinogalactan structure by the action of ethambutol at the concentration 40 μg/ml, at which the cell growth was apparently not affected, caused the decrease of the product formation from 135 mg/1 to 70 mg/1. In the presence of isoniazid (350 μg/ml) only trace amounts of AD accumulated during 48 hours of transformation indicating much lower activity than that of the intact cells. The most effective among the tested inhibitors of peptidoglycan synthesis were glycine (15 mg/ml) and vancomycin (150 μg/ml) which enhanced the transformation activity of the treated cells nearly three times. Increased transformation rate was also obtained by the action of colistin at concentrations rang

ISSN:0233-111X    

DOI:10.1002/jobm.3620340605

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe arginine and proline inhibition of nitrite reductase and urease activities have been studied in the cyanobacteriumAnabaena cycadeaeand its mutant strain lacking glutamine synthetase (GS)1) activity. Arginine and proline inhibited the nitrite reductase and urease activities in the parent strain, however, they could not do so in the mutant strain. The level of arginine‐ and proline‐dependent NH 4−production in the outer medium was several fold higher in the mutant strain as compared to its parent strain. These results suggest that (1) nitrite reductase and urease activities are arginine‐ and proline‐repressible; (2) the catalytic function of GS is necessarily required for the arginine and proline inhibition of nitrite reductase and urease systems; and (3) the NH 4−resulting from the catabolism of arginine and proline should be metabolized via GS for repression of nitrite reductase and

ISSN:0233-111X    

DOI:10.1002/jobm.3620340606

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractSolid‐state fermentations have attracted renewed interest and attention from researchers due to recent developments in the field of biotechnology. In this article some aspects of solid‐state cultivations have been reviewed, including characteristics of substrates and microorganisms used for various endprodu

ISSN:0233-111X    

DOI:10.1002/jobm.3620340607

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThis paper covers the recent data on the biosocial interactions of microbial cells in populations. These interactions are considered in terms of general ethological and sociobiological concepts such as agonistic behaviour, affiliation, cooperation and coordination. Microbial social behaviour exemplified by the interactions among individuals in the supraorganismic structures of myxobacteria,Proteus mirabilis, Escherichia coli, myxomycetes and fungi is compared (i) to the cell behaviour involved in the development of animal embryos and immune responses of multicellular organisms and (ii) to the collective behaviour of higher animals in groups or communities. Special attention is given to the biotechnological implications of microbial sociality.

ISSN:0233-111X    

DOI:10.1002/jobm.3620340608

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620340601

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY