The microbial bioleaching communities which is commonly consisted by a vast variety of microorganisms in mining system, complex microbial interactions and nutrient patterns are still yet systematically understood and mastered [74] and [75]. In spite of the accelerated development of biohydrometallurgy,

there are only a modest number of iron(II)- and sulfur oxidizing bacteria have been isolated from metal sulfide ores, described systematically and phylogenetically [76] and [77]. There are several reviews that afford the comprehensive and relatively complete descriptions of the mesophilic, moderately thermophilic, extremely thermophilic bacteria and archaea involved in biohydrometallurgy, and there are several recent reviews that conclude the microbial diversity related to the bioleaching and biooxidation in detail [9], [10], [21], Fluorouracil [78], [79] and [80]. In terms of the ferrous- and sulfur-oxidizing chemolithotrophic microorganism, the acidophilic bacteria and archaea are preferred in biohydrometallurgy [79]. These acidophilic bacteria and archaea widely distributed and adapted well. They can be cultured and isolated from environments

such as hot springs, volcanic regions and acid mine drainage [74] and [75]. The techniques such as denaturing gradient gel electrophoresis (DGGE), 16SrRNA sequencing, PCR-based methods and fluorescence in situ hybridization (FISH) are used for the identification of the specific

EPZ-6438 molecular weight microorganism. Mesophilic and moderately thermophilic microorganisms spanned four bacteriophyta, the Proteobacteria, Nitrospirae and Actinobacteria and the extremely thermophilic archaea mostly classified to the Sulfolobales [8] and [81]. Pradhan et al. provided the HSP90 listing of the autotrophic and heterotrophic bacteria and archaea that can be utilized. Silverman and Ehrlich proposed that bacteria or microorganisms oxidize metal sulfide ores or deposits by a direct mechanism or an indirect mechanism. According to the different electronic extraction processes, the process that the electrons are directly transferred to the cell attached to the mineral surface from the metal sulfide is called direct bioleaching. The process that the electrons are transmitted to the oxidizing agent of the sulphide ores, ferric ions, is called indirect bioleaching. Tributsch proposed that the term “contact” leaching be used in place of “direct” leaching based on the attachment and planktonic phenomenon of the bacteria in the process of leaching [82]. Rawlings suggested that the process of the dissolution of metal sulfide and intermediates by planktonic bacteria should be described as “cooperative leaching” [12].