摘要:

AbstractThe acidophilic methylotrophicAcetobacter methanolicusMB 58 possesses a complete set of TCA cycle enzymes. As in neutrophilic methylotrophs, during growth on C1‐compounds the cycle in acidophilic methylotrophs does not work to yield energy. This is also true for chemoheterotrophic growth ofAcetobacter methanolicus. However, in the non‐methylotrophicAcetobacter pasteurianuswhen grown on glycerol, the citric acid cycle seems to operate to yield ene

ISSN:0233-111X    

DOI:10.1002/jobm.3620280112

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractStreptomycetes continuously cultivated in a chemostat exhibit a bistable growth pattern characterized by two different growth behaviours, a “disperse” one and a “pellet” one. There exists a distinct range of growth rates within which either growth behaviour can be exerted. The transition between them can be induced by shifting the growth rate above or below critical values by manipulating the dilution rate. Both of them are stable over the same range of growth rates provided that the changing of growth rate within this stability range proceeds successively in moderate steps. This bistable growth pattern is exerted at least by two different species,Streptomyces nourseiandStreptomyces “

ISSN:0233-111X    

DOI:10.1002/jobm.3620280113

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractPurification by DNA‐cellulose chromatography of acid‐soluble DNA‐binding proteins (ASB) fromStreptomyces hygroscopicusis described. Two main fractions, ASBII and ASBIII, containing different major protein components were isolated. The dominating protein of ASBIII (19 kd) could be enriched onStreptomycesDNA‐cellulose.DNA‐binding properties of ASBIII were studied by using a filter retention assay, thermal melting, and by following the DNA template activity in the RNA polymerase system ofE. coli. Binding to supercoiled and linear pBR322 DNA occurred effectively at 0.05 M NaCl while increasing salt concentrations up to 0.15 M and 0.2 M NaCl caused dissociation of the complexes. Single‐stranded DNA showed a slightly lower affinity for the ASBIII protein. ASBIII blocked the DNA template activity of the RNA polymerase reactionin vitro. The binding properties and role of ASB‐proteins are discussed with respect to their possible influence on the chromosomal sta

ISSN:0233-111X    

DOI:10.1002/jobm.3620280114

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractColicins attach themselves — through specific protein‐protein interactions — onto receptors in the outer membrane of sensitive bacterial cells. An attempt was made to analyze amino‐acid groups and attractive forces involved in this interaction, following treatment of either colicins A, E2, E3 and K or sensitive bacteria with various physico‐chemical factors and several protein‐modifying reagents. The amounts of colicin bound were checked by a quantitative biological assay.Ionic conditions and specific spatial conformation of both colicin and its receptor molecules are crucial in their interaction and, hence, in the biological effect of colicin.Formaldehyde, naphthalene‐diisocyanate and osmium tetroxide strongly inhibit the binding ability of all colicins tested. The results suggest that NH2and SH groups are involved in their binding onto receptors; also, CH3S groups seem to be engaged in the attachment of colicins E2 and E3 and phenol‐OH groups in that of colicin K. The possible involvement of further groups (NH, SH etc.) should be checked using more specific reagents. The attitude of colicins E2 and E3 to their common receptorBtuBprotein is nearly, but not completely the same.Receptors for all colicins tested should be oxidized to achieve optimal interactions; obviously, carbonyl groups are produced and newly formed anions increase the negative load of bacterial surface. In agreement, reduction of at least colicins A and E3 enhances their receptor binding reactivity. The binding capacity of each receptor can be modulated by a set of amino acid reagents in a

ISSN:0233-111X    

DOI:10.1002/jobm.3620280115

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractStreptothricin resistance determinants have been cloned from the transposons Tn1825 and Tn1826 to the vector plasmid pUC8. The recombinant plasmids were characterized with respect to their physical structure. The resistance properties of their hosts were characterized with respect to the minimal inhibitory concentration of streptothricin and the activity of the streptothricin acetyltransferase. The proteins encoded by the cloned resistance determinants were analysed in a maxicell system. The results of our investigations suggest that the resistance to streptothricin is mediated by the activity of a streptothricin acetyltransferase with both, Tn1825 and Tn1826. However, the resistance determinant of Tn1825 is more complex than Tn1826 and additional functions involved in realizing the resistance phenotype must be recognized.

ISSN:0233-111X    

DOI:10.1002/jobm.3620280116

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractRecent biosynthetic studies confirmed that anthraquinones are involved as intermediates in the pathway to anthracyclines. The present knowledge in this field has been reviewed. Furthermore, a new generalized order of biosynthetic intermediates from the hypothetical polyketide to aklavinone and related anthracyclinones has been proposed involving tricyclic precursors and 7‐hydroxy‐naphthacenequinones, which also have been found in mutants of anthracycline‐producing st

ISSN:0233-111X    

DOI:10.1002/jobm.3620280117

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280101

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY