Enzymic comparisons of the inorganic sulfur metabolism in autotrophic and heterotrophic Thiobacillus ferrooxidans.

Activities of enzymes which mediate the oxidation of thiosulfate to sulfate and the assimilation of sulfate to sulfide were assayed in various cell-free fractions of Thiobacillus ferrooxidans grown autotrophically on either ferrous iron or thiosulfate or heterotrophically on glucose. There was no activity of the thiosulfate-oxidizing enzyme in extracts of bacteria grown with ferrous iron. Comparable activities for ATP-sulfurylase (EC 2.7.7.4), ADP-sulfurylase (EC 2.7.7.5), and adenylate kinase (EC 2.7.4.3) were found in the bacteria grown autotrophically with either Fe2+ or S2O32- or heterotrophically with glucose.