title: Respiratory properties of cytochrome-c-deficient mutants of Azotobacter vinelandii.
abstract: Cytochrome-c-deficient mutants of Azotobacter vinelandii have been isolated following mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. These mutants grow well under nitrogen-fixing conditions and studies of the physiology and energy conservation efficiency show no apparent differences from those of the parent strain. Under oxygen-limited growth conditions, the growth rate of the cytochrome-c-deficient mutant was slightly slower (approx. 15%) than that of the parent strain. Cytochromes of the c-type are required for the oxidation of artificial electron donors such as reduced N,N,N',N'-tetramethyl-p-phenylenediamine [Ph(NMe2)2]. This study could not demonstrate a physiological role for the c-type cytochromes which supports the idea that the minor Ph(NMe2)2-oxidizing pathway of the electron transport chain may be independent of the major pathway terminated by cytochrome d.
mesh_terms: D001395:Azotobacter / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D002248:Carbon Monoxide; D003574:Cytochrome c Group / Q000378:metabolism*; D007700:Kinetics; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D009154:Mutation; D010101:Oxygen Consumption; D013053:Spectrophotometry; D013772:Tetramethylphenylenediamine
chemical_list: D003574:Cytochrome c Group; D008769:Methylnitronitrosoguanidine; D002248:Carbon Monoxide; D013772:Tetramethylphenylenediamine