Peculiarities of Adhesion and Bioleaching of Pyrite by New Isolated Leptospirillum Spp. Bacteria

Abstract

Leptospirillum sp. str. ZC isolated from bioleaching pulp of zinc concentrate is capable of oxidizing Fe (II) with the optimal temperature of 37℃. In pure culture bacteria is unable to oxidize pyrite, however, its growth together with sulfur oxidizing A.albertensis str.SO -2 significantly enhances the efficiency of pyrite bioleaching. The correlation between pyrite biooxidation and adhesion of Leptospirillum spp. bacteria on mineral surface has been found. It has been revealed that in case of mixed culture the cells of Leptospirillum sp. str. ZC are adhered on pyrite surface only after its initial colonization by sulfur oxidizing bacteria. It is supposed that bioleaching of pyrite by Leptospirillum spp. bacteria occurs by means of indirect contact leaching.