title: Hydrogen metabolism and nitrogen fixation in wild type and Nif- mutants of Rhodopseudomonas acidophila.
abstract: N2 fixation, C2H2 reduction and H2 production in Rhodopseudomonas acidophila DSM 137 were shown to be stoichiometrically related in ratios of 1:2.8:2.8. The highest possible H2 oxidation rate has been calculated to be about 6 fold higher in Rhodopseudomonas acidophila DSM 137 than the maximum rate of H2 production. Nif- mutants were isolated and tested; all of them had lost their ability of reduce C2H2 and to produce H2. In two nif- mutants hydrogenase activity and the capacity for autotrophic growth with H2 were also strongly diminished. Nif+ revertants not only regained their ability for C2H2 reduction and H2 production but also their full capacity for autotrophic growth with H2.
mesh_terms: D006859:Hydrogen / Q000378:metabolism*; D007700:Kinetics; D009154:Mutation; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000378:metabolism*; D012241:Rhodopseudomonas / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D006859:Hydrogen; D009591:Nitrogenase