Dissimilatory sulfate reduction plays an important role in removal of dissolved metals from acidic mine waters. Although this process was convincingly shown to occur in acidic waste of metal recovery, few isolates of acid-tolerant sulfate rducers are known. We isolated a new acidophilic sulfidogen, strain BG, from the oxidized acidic waste of the Bom-Gorkhon tungsten deposit, Transbaikalia, Russia. Phylogenetic analysis of its 16S rRNA gene sequence made it possible to identify it as a member of the genus Desulfosporosinus. Unlike other known acidophilic sulfate reducers of this genus, strain BG was tolerant to high copper concentrations (up to 5 g/L), could grow on organic acids at low ambient pH, and formed crystalline copper sulfides (covellite and chalcopyrite). Molecular analysis of the phenotypes predominating in oxidized waste and in enrichment cultures confirmed the presence of various Desulfosporosinus strains.