Haematin-dependent Oxidative Phosphorylation in Streptococcus faecalis

SUMMARY Functional cytochrome(s) and an oxidative phosphorylation system were demonstrated in Streptococcus faecalis grown on media supplemented with haematin. The membrane fraction of cell-free extracts coupled the oxidation of reduced NAD to the formation of ATP from ADP and in organic phosphate. This reaction was sensitive to cyanide, azide and Antimycin a. A b 2 type cytochrome was detected in the membrane fraction with absorption maxima at 412, 425, 529 and 559 nm.