The path of sulfur during the bio-oxidation of pyrite by Thiobacillus ferrooxidans

The detection of colloidal sulfur with dimensions of 20 (sometimes up to 70) to 4 nm as intermediates of sulfide bio-oxidation by Thiobacillus ferrooxidans presents new possibilities for the exploration of the leaching mechanism of inorganic sulfides and for the use of sulfur in bacterial metabolism. The liberation of sulfide-S from a crystallized compound in an interfacial reaction, the formation and stabilization of colloids (by biological macromolecules) in an organic capsule around the bacterial cell and the life cycle of colloids during the leaching, including their final consumption, are discussed. An illustration is provided explaining the generation, stability and metabolism of sulfur from pyrite by Thiobacillus ferrooxidans. (C) 1996 Elsevier Science Ltd.