摘要:

AbstractStreptomyces purpurascenstransforms primary and secondary 12‐deoxycardenolids into digoxin, 7β‐hydroxy‐digitoxin and 7β‐hydroxy‐digoxin, respectively. A metabolic pathway is proposed for cardenolid transformations and the enzymes participating in it are investigated. The substrate concentration in the medium can be increased by using a water‐miscible solvent of electron donor character. The newly developed procedure yields 0.5 g/l−1of digoxin in a five

ISSN:0044-2208    

DOI:10.1002/jobm.19820220702

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA respiration‐deficient mutant ofSaccharomyces cerevisiae, grown aerobically with glucose as the sole source of energy and carbon, showed residual respiration resistant to cyanide. The differential sensitivity of cell fractions to inhibition by hydroxamic acids and carbon monoxide suggested that more than one type of organelle, probably mitochondria and microsomes, was involved in the consumption of oxyge

ISSN:0044-2208    

DOI:10.1002/jobm.19820220703

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA bacterium capable to lyse viable yeast cells was isolated from compost enriched with baker's yeast cells and was identified asArthrobacter globiformis.The yeast lytic enzyme complex produced by shaking culture was precipitated with ammonium sulfate, dialyzed and lyophilized. The crude residue contained β‐glucanase and α‐mannanase, yet not chitinase. Optimale carbon sources in the culture medium for a high enzyme synthesis were 0.5% β‐glucan for the production of β‐glucanase, resp., 3% α‐mannan for the production of α‐mannanase. Addition of 10% whole died baker's yeast cells to the culture medium effected similar results.The crude enzyme residue released among other things spheroplasts from cells of the yeastPichia membranaefaciens, Metschnikowia pulcherrima, Hansenula anomalaandCandida guilliermondii“H”. However, it did not or only weakly lyse viable cells of the yeastsRhodotorula rubra, Rhodosporidium toruloidesandSporobolomyces roseus.The mutants ofCandida guilliermondii“H” with modified glucan, resp., mannan concentrations in the cell walls did not indicate differences in thei

ISSN:0044-2208    

DOI:10.1002/jobm.19820220704

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractAcetobacter sp.MB 58 assimilates methanol via the fructose‐1,6‐bisphosphate variant of the hexulose phosphate pathway. Glyceraldehyde‐3‐phosphate originates as net product of an assimilation loop involving the regeneration of the C1‐acceptor ribulose‐5‐phosphate and must be available for thede novosynthesis of the C1‐acceptor as well as for the oxidative glycolysis.It is made probable in a regulatory model that this is accomplished via alternating anabolic and catabolic phases which are controlled by concerted action of PEP‐carboxylase and pyruvate kinase. Whereas Ac‐CoA is a crucial effector and ä‐ketoglutarate and aspartate are inhibitors for the PEP‐carboxylase, the pyruvate kinase is assumed to be re

ISSN:0044-2208    

DOI:10.1002/jobm.19820220705

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractStrains ofEscherichia coliK12 harbouring ColV‐K94 contain a new major outer membrane protein of molecular weight ca. 33,000. The new protein resembles theOmp Aprotein in that (1) it is trypsin‐sensitive in membrane preparations and (2) it is not murein‐associated. The new protein cannot, however, replace theOmp Aprotein as a functional receptor for the phages K3 and Tull*, for colicin L or for efficient conjugation with F‐like donors. The new protein is apparently not a transfer component and is produced by cells unable to produce colicin. Labelling experiments with minicells suggest that the new protein is one of two major plasmid‐encoded membrane

ISSN:0044-2208    

DOI:10.1002/jobm.19820220706

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractMore than 27% of the cell wall are unstably bound components: Proteophosphomannan as a main polysaccharide of the cell wall, mannose and manno‐oligosides which are bound to peptides or phosphate.19% are glycosidically linked with a phosphate bridge or 0‐glycosidically (Ser/Thr) linked with the protein which is covalently bound to the cell wall. Besides mannose and glucose, manno‐oligosides and gluco‐oligosides are involved in this linkage.A preparation consisting of glucan and chitin remains after careful degradation. It contains (1,2)‐, (1,3)‐ and (1,6)‐ linked glucose, (1,2,3)‐, (1,2,6)‐ or (1,3,6)‐glucose‐branchpoints and (1,4)‐lin

ISSN:0044-2208    

DOI:10.1002/jobm.19820220707

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractTransfection by DNA isolated from bacteriophage T3 was studied usingEscherichia coli921/0 as host. The following conditions were found optimal:CompetentE. coli921/0 were obtained by harvesting the bacteria at the onset of late exponential growth (5 × 108cells/ml) and treating the latter with 0.05 M CaCl2. Hereafter, the microbes were suspended in 50 mM Tris‐HCl buffer (pH 7.2) and the concentration adjusted to 7 × 109cells/ml. T3 DNA was added and the suspension kept at 0°C for 15 min. Determination of the number of infectious centers was then carried out in the usual way. The efficiency of transfection under these conditions amounted to 104p. f. u./μg DNA.Preincubation of competent bacteria with T4 DNA at 0°C before the addition of T3 DNA reduced the number of infectious centers. However, if T3‐ and T4 DNA were added simultaneously no decrease of the transfection efficiency occurred. Calf thymus DNA was without influence on tran

ISSN:0044-2208    

DOI:10.1002/jobm.19820220708

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe programme of protein synthesis as an indicator for the control of gene expression was examined during outgrowth ofBacillus subtilisspores. At various stages of outgrowth cells ofBacillus subtiliswere labelled with35S‐L‐methionine. Extracted proteins were separated on two‐dimensional gels according to O'FARRELL (1975). Three groups of proteins were synthesized during outgrowth:1During all stages of outgrowth a great number of “vegetative genes” is expressed. The programme of protein synthesis of the outgrowing cell is very similar to that of a vegetative cell.2Only a few proteins — probably the products of outgrowth‐genes — are synthesized especially in outgrowing spores and turned off at different stages of outgrowth.3The synthesis of a minor group of vegetative proteins is triggered during different stages of outgrowth.In contrast to earlier assumptions (comp. TORRIANI and LEVINTHAL 1967, HANSENet al.1970, GALIZZIet al.1976) we suggest that only a small portion of the genome is activated during outgrowth as a dependent sequence.These results are discussed on the basis of earlier concepts about the regulation of outgrowth as a developmentally regulated gene expre

ISSN:0044-2208    

DOI:10.1002/jobm.19820220709

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA strain ofLipomyces kononenkoaeearlier proposed for industrial starch bioconversion was found to have a dissociative temperature profile. The ARRHENIUS plot of sustained exponential growth displayed a single branch between the optimum (32–33°C) and the maximum (about 35°C) temperature for growth while the extrapolated ARRHENIUS plots of growth and thermal death intersected at a biologically non‐significant value. The yield ofL. kononenkoaeon glucose did not decrease at supraoptimal temperatures while the associative yeastSaccharomyces cerevisiaesuffered yield decreases above the optimum temperature for growth with increasing temper

ISSN:0044-2208    

DOI:10.1002/jobm.19820220710

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19820220711

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY