With the continuous development of biological metallurgy,it has become more and more important to research into the microorganisms used for bioleaching As the main components of complex microbial system,Acidithiobacillus ferrooxidans.A.thiooxidans and A.calduscould utilizeelement sulfur and reduced inorganic sulfur compounds(RISCs)such as polysulfide,sulfite and metal sulfide,resulting in the importance in the field of bioleaching,the treatment of sulfide-bearing wastewater,coal desulfurization and even sulfur cycle in nature.