title: Oxygen requirement for acetylene reduction by pure cultures of rhizobia.
abstract: The oxygen and nutritional requirements for acetylene reduction by Rhizobium japonicum and Rhizobium sp. in liquid culture are described. The optimal oxygen concentration was about 0.1% in the gas phase, which is lower than that of any other known aerobic nitrogen-fixing microorganism. these organisms are also unique in that nitrogenase synthesis is not repressed in the presence of ammonium chloride under certain cultural conditions, in contrast to other wild-type bacteria.
mesh_terms: D000114:Acetylene / Q000378:metabolism*; D000643:Ammonium Chloride / Q000494:pharmacology; D004794:Enzyme Repression; D009591:Nitrogenase / Q000096:biosynthesis; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D012231:Rhizobium / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000643:Ammonium Chloride; D009591:Nitrogenase; D000114:Acetylene