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Nutritional Requirement for the Expression of Nitrogenase Activity by Rhizobium sp. in Agar Culture
Author(s) -
PANKHURST C. E.
Publication year - 1981
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1981.tb00869.x
Subject(s) - nitrogenase , derepression , strain (injury) , asparagine , biochemistry , agar , biology , food science , rhizobium , chemistry , bacteria , microbiology and biotechnology , nitrogen fixation , enzyme , genetics , psychological repression , gene expression , anatomy , gene
The effect of various carbon sources, nitrogen sources, vitamins and trace elements on the ability of three strains (32H1, CB627, CB744) of a slow‐growing Rhizobium sp. to develop nitrogenase activity in agar culture was studied. Strains 32H1 and CB627 developed nitrogenase but showed differences with respect to the nature and concentrations of carbon sources required for optimum activity. Strain 32H1 had less specific requirements than CB627 in this respect and could sustain high nitrogenase activity over a wider range of phosphate concentration (5 to 60 mmol/1) in the medium than CB627. There were only minor differences between these two strains with respect to the nitrogen source [glutamine, asparagine, histidine or (NH 4 SO 4 ] required in the medium for nitrogenase induction, and nitrogenase activity in both strains was unaffected by changes in the concentration of vitamins or trace elements supplied. Strain CB744 did not develop nitrogenase activity under any of the conditions tested. Adenosine 3′, 5′‐cyclic monophosphate (1 mmol/1) was found to accelerate derepression of nitrogenase synthesis in agar cultures of strains 32H1 and CB627.