Hydrogen oxidation by membranes from autotrophically grown Alcaligenes eutrophus H16: role of the cyanide-resistant pathway in energy transduction.

Eighty percent of the ATP and proton electrochemical gradient (-ZDeltapH) formed during H2 oxidation in membranes from autotrophically grown exponential-phase cells of Alcaligenes eutrophus H16 was derived from a redox pathway that includes the membrane-bound hydrogenase complex and the cyanide-resistant (bo-type) oxidase. The H2/ubiquinone-1 oxidoreductase activity was coupled to energy transduction and was fully inhibited by the quinone along 2-n-hepthyl-4-hydroxyquinoline-N-oxide. We conclude that the cytochrome-c-containing pathway in exponential-phase A. eutrophus H16 cells plays a minor role in energy conservation.