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Anabole und katabole Enzyme des Harnstoffmetabolismus in einem kohlenwasserstoffverwertenden Stamm von Candida guilliermondii
Author(s) -
Metz W.,
Reuter G.
Publication year - 1977
Publication title -
zeitschrift für allgemeine mikrobiologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0044-2208
DOI - 10.1002/jobm.19770170804
Subject(s) - arginase , urea , yeast , urease , biochemistry , catabolite repression , ornithine , chemistry , ammonia , catabolism , enzyme , urea cycle , arginine , amino acid , mutant , gene
The yeast „H” of the genus Candida guilliermondii can grow on hydrocarbons as the only source for carbon. Urea can serve as a nitrogen source for this yeast which lacks detectable urease activity. During urea metabolism ammonia has never been accumulated in the culture medium. However, transferring the yeast from complete urea‐medium into an urea containing phophatebuffer, the degradation of urea continues and ammonia is accumulated as well as CO 2 evolved. In cell‐free extracts of the yeast urea amidolyase activity was detected in the presence of ATP, biotin and specific cations. Obviously, the synthesis of urea amidolyase is induced by urea and arginine and repressed by the catabolite ammonia. Similarly the synthesis of arginase is regulated by arginine and ammonia. The analytical data of the arginase action differ significantly in relation to the carbon source of the culture medium. Both the level of arginase and ornithine carbamyltransferase change in a characteristic way during the batch‐culture. From the lower level of arginase in relation to ornithine carbamyltransferase it can be concluded that especially in alkane‐metabolizing yeast the arginine catabolism is not very intensive.