MICROÖRGANISMS CONCERNED IN THE OXIDATION OF SULFUR IN THE SOIL II. THIOBACILLUS THIOOXIDANS, A NEW SULFUR-OXIDIZING ORGANISM ISOLATED FROM THE SOIL

Abstract

By composting sulfur, rock phosphate and soil it was found that sulfur is rapidly oxidized to sulfuric acid; the acid acts upon the tricalcium phosphate, converting it into di-andmono-calciumsalts. In the absence of a neutralizing agentor,after this agent has all been used up,the sulfuric acid formed, in the presence of an excess of sulfur, accumulates in the medium. On inoculating such composts into proper culture media, we finally succeeded in isolating a small bacterium which is active in the oxidation of the sulfur. A detailed study of the composting of sulfur, of the transformation of the tri-calcium phosphate and of the methods used in the isolation of the organism are found elsewhere; only a brief review of the process of isolation is presented here.