Study on metabolic mechanisms of sodium thiosulfate by Thiobacillus Ferrooxidans and Thiobacillus Thiooxidans

In this research, Thiobacillus ferrooxidans (T.f) and Thiobacillus thiooxidans (T.t) were obtained from a hot spring containing sulfur after a series of cultivating, separating and purifying. And sodium thiosulfate was added to the culture of these two bacteria respectively in a certain concentration. Then the growth features of the two bacteria, variation of concentration of different sulfur compounds were investigated under different levels of dissolved oxygen. Results showed that: (1) the oxidation velocity of thiosulfate by T.f was higher and the growth period of T.f was shorter than that of T.t. However, the metabolic capability of a single cell of T.f was weaker than that of T.t; (2) The main metabolic products of sodium thiosulfate by T.f and T.t were sulfate ion, tetrathionate ion, sulfur dioxide and elemental sulfur. Thiosulfate ion was metabolized by T.f and T.t through four main paths; (3) Oxidation rates of sodium thiosulfate by T.f and T.t could be accelerated by increase of dissolved oxygen.