Abstract: Biohydrometallurgy involves diversified microorganisms and up to now, bacteria of 13 genera are reported to have relation with bioleaching of metal sulfides.The bioleaching of metal sulfides can involve three mechanisms, namely, indirect bioleaching, contact bioleaching and cooperative bioleaching, with the indirect bioleaching following two functional pathways: thiosulfate and polysulfide.Though bacterial mixture bioleaching offers many advantages over that of using a single bacterium, it also has some unfavorable effects and its bioleaching mechanism is not very clear now.Therefore, to better utilize biohydrometallurgy technology, research on bacterial mixtures should be intensified for controlling their composition and activity so as to optimize the biohydrometallurgical process.

Key words: Biohydrometallurgy, Bacterial mixture, Functional mechanism