[Effect of growth conditions on substrate phosphorylation during sulfite oxidation in Thiocapsa roseopersicina]

Cell extracts of Thiocapsa roseopersicina, strains BBS and SL, grown in the light under anaerobic conditions and in the dark under aerobic conditions on a medium containing thiosulphate produce ATP during oxidation of sulphite in the presence of AMP cytochrome c and inorganic phosphate. The uncoupling agent (m-chlorocarbonylcyanidephenylhydrazone) has no effect on the rate of ATP production, this being an evidence of substrate phosphorylation. The rate of ATP synthesis is higher in extracts of the cells grown in the dark under autotrophic conditions than in extracts of the cells cultivated in the light under anaerobic conditions or in the dark in the presence of thiosulphate and glucose.