摘要:

AbstractThe degradation of cholesterol side chain was studied by immobilized cells ofNocardia erythropolisin the presence of an inhibitor of the microbial steroid‐skeleton‐degradation. Different immobilized preparations such as DEAE‐cellulose adsorbates, ionic cross‐linked polymer gels,i.e., A1/Coalginates and polyacrylates, respectively, and polyethylene maleic acid anhydride supports have shown a high transformation activity yielding the C22‐ and C19‐degradation products. No side chain degradation activity could be observed after immobilization of the cells in polyacrylamide gel under usual conditions caused by the toxic effect of the acrylamide monomer on theNo

ISSN:0044-2208    

DOI:10.1002/jobm.19800200302

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractDie Formiat‐Dehydrogenase (E. C. 1.2.1.2.) kommt in allen — bisher untersuchten — „Serinweg‐Bakterien”︁ vor, und sie wird induziert durch Methanol und durch Formiat auch bei Bakterienstämmen mit konstitutiver Methanol‐Dehydrogenase, obwohl der von der Formiat‐Dehydrogenase katalysierte Schritt außerhalb des Assimilationszyklus liegt.Die Formiat‐Dehydrogenase ist bei hinreichend hoher Carbonatkonzentration im Wachstums‐medium für biosynthetische Reaktionen ohne Bedeutung. Sie ist für den Energiehaushalt dieser Bakterien wesentlich. Darauf weist hin, daß die energetisch negative Bilanz des Assimilationszyklus durch Einbeziehung der Formiat‐Dehydrogenase‐Reaktion positiver wird. Gegenüber ATP ist die Formiat‐Dehydrogenase — ausPseudomonas methylica— unempfindlich. Da dieses Enzym mit der induktiven biosynthetischen Formyltetrahydrofolat‐Synthetase (E.C. 6.3.4.3.) um Formiat konkurriert und letzteres Enzym ATP als Substrat hat, kann ATP trotzdem das Gleichgewicht von Assimilation und Dissimilation allein via Massenwirkungsgesetz wirksam kontrollieren. Bei niedriger ATP‐Konzentration ist die bioenergetische Formiat‐Dehydrogenase begünstigt und bei hoher wird Formiat bevorzugt assimiliert. Aber wesentlicher für die Lage des Gleichgewichts scheint das NAD+/NADH‐Verhältnis, genauer gesagt, die NADH‐Konzentration zu sein, denn NADH hemmt die Formiat‐Dehydrogenase kompetitiv gegenüber NAD+und nicht‐kompetitiv gegenüber Formiat.NADH spielt also im methylotrophen Stoffwechsel nicht nur die für andere Ernährungstypen (z. B. aerobe chemoorganoheterotrophe Ernährung) übliche Rolle, sondern es ist außerdem Su

ISSN:0044-2208    

DOI:10.1002/jobm.19800200303

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

摘要:

Abstract75 species which belong to 25 genera were collected during this investigation. All of these fungi were previously isolated from Egyptian soils and other sources. The total count and the number of genera and species in the rhizosphere soil of the 5 plants were regularly higher than in non‐rhizosphere soil.The composition of the rhizosphere fungus flora was considerably influenced by the type and the age of the plant. The most prevalent fungi in the rhizosphere of the test plants after 45, 90, and 150 days were as follows: inHelianthus annuus, Stachybotrys atraandAspergillus niger; inChrysanthemum coronarium, Cladosporium herbarum, A. sydowiiandPenicillium funiculosum; inNigella sativa, Fusarium moniliformeandA. sydowii; inDatura innoxia, A. fumigatusandA. terreus; inHyoscyamus muticus, C. herbarumandA. sydowii; and in soil,P. funiculosum, A. terreusandA. niger. The counts of total fungi and most of the common fungal species, except in the case ofDatura innoxia, reached their maxima after 90 days and sharply declined after 150 day

ISSN:0044-2208    

DOI:10.1002/jobm.19800200304

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

摘要:

Abstracto‐Aminobenzoic acid (OABA) known by its stimulatory effect on streptothricin biosynthesis byStreptomyces nourseiJA 3890b was found to suppress specifically the formation of cytochromea‐type terminal oxidase while the levels of theb‐ andc‐type cytochromes apparently remained unaffected. This change was coupled to decreased capacity of transport of u‐14C‐L‐alanine and u‐14C‐L‐glutamic acid into the mycelium, giving rise to delay of amino acid catabolism and decreased production of nitrogen catabolites within the cell. The above results provide supporting evidence for conjectures recently published by us concerning the control by nitrogen catabolites of the secondary metabolism of this strain. As a summary a scheme is proposed showing several hypothetic mechanisms by which nitrogen catabolite regulation of nourseothricin production co

ISSN:0044-2208    

DOI:10.1002/jobm.19800200305

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractThe influence of methylbenzimidazol‐2‐yl carbamate (MBC) on the cyclic nucleotide system of germinatingAspergillus nidulansconidia has been investigated throughout the cell cycle.The content in cyclic adenosine 3′,5′‐monophosphate (cAMP) and cyclic guanosine 3′,5′‐monophosphate (cGMP) is rapidly decreased in the course of conidia swelling and has been found not to be influenced by MBC. On the other hand, influence of MBC leads, in inhibited nuclear division, to a significant increase of the intracellular cAMP level in theG2‐period between the eighth and tenth hour after incubation. The adenylate cyclase activity has not been significantly influenced during this period by MBC treatment. On the contrary, the cAMP‐specific phosphodiesterase activity has been decreased. The cGMP content of germinating conidia decreased, contrary to cAMP by MBC treatment between the seventh and twelfth hour. Activity of guanylate cyclase has been generally stimulated in the presence of MBC, whereas that of the cGMP‐specific phosphodiesterase as a result of mitosis inhibition has been blocked.The influence of the cyclic nucleotide system on mitosis is discussed in terms of

ISSN:0044-2208    

DOI:10.1002/jobm.19800200306

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19800200307

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19800200308

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19800200309

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19800200312

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19800200314

出版商:Akademie‐Verlag    

年代:1980

数据来源: WILEY