Oxidative Phosphorylation in Micrococcus denitrfricans

Abstract

An ATP-supported reduction of NAD⁺ by succinate was demonstrated in membrane fragments prepared from aerobically grown cells of Micrococcus detnitrificans. Evidence was obtained to indicate that the reaction involved a reversal of electron and energy transfers in oxidative phosphorylation at the NADH-cytochrome b segment of the respiratory chain. Inhibitors of the electron transfer at this segment and those of the energy transfer of oxidative phosphorylation were all effective toward the NAD⁺reduction process. Conditions affecting the rate of the reaction were also studied.