BIOCHEMICAL STUDIES ON SULFATE-REDUCING BACTERIA

Abstract

Hydrogenase and thiosulfate reductase were isolated separatively from the 0.9% NaCl extract of bacterial cells by centrifugation (15,000 rpm), and by fractionation of the supernatant with (NH4)2SO4 between 0.33 and 0.67 saturations. Both enzyme preparations catalzye S2O3 reduction in the presence of H2 and of methylviologen. Cytochrome was isolated from paline extract by acetone precipitation (33%), followed by acetone fractionation between 33 and 67%; green pigment was isolated simply by fractionation with acetone between 33 and 67%. The cytochrome shows 3 peaks at 553, 525 and 411 m[mu] in reduced form and a peak at 410 m[mu] together with a shoulder at 525 mix in the oxidized state. The pigment gives 4 absorption bands at 630, 585, 410 and 390 mu[mu], and is not reduced by Na2S2O4.