title: Differentiation of Rhizobium japonicum, III. Inhibition of nitrogenase derepression by chloramphenicol and rifampicin concentrations, not inhibiting growth.
abstract: Development of nitrogenase (40--140 nmol C2H4.mg protein-1.h-1) in Rhizobium japonicum 61-A-101 after transfer to special culture conditions (medium 20 P, 2% O2, 10% CO2, 88% N2 in the gas phase) is inhibited by chloramphenicol (6 X 10(-4)--10(-3) M) and by rifampicin (10(-5) M). These concentrations do not inhibit the slow growth of the cells under these conditions with a doubling time of the cell protein and living cell number of 3--5 d. Nitrogenase activity of previously derepressed cells is not inhibited by chloramphenicol. Growth of the cells under air in yeast extract-mannitol-glycerol medium (8 h doubling time) is affected significantly more by chloramphenicol (2.5 X 10(-4) M) than growth under nitrogenase derepressed culture conditions.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology*; D004794:Enzyme Repression / Q000187:drug effects; D007700:Kinetics; D009591:Nitrogenase / Q000378:metabolism*; D012231:Rhizobium / Q000201:enzymology* / Q000502:physiology; D012293:Rifampin / Q000494:pharmacology*
chemical_list: D002701:Chloramphenicol; D009591:Nitrogenase; D012293:Rifampin