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DGGE (denaturing gradient gel electrophoresis) technology is widely used in the analysis of microbial populations. In this paper, the technology shake flask cultures of nickel sulfide ore, copper sulfide ore agitation leaching and column leaching three leaching system for the analysis of the structure of bacterial populations, and to explore the relationship between the bacterial population structure and the leaching rate of the leaching system . To a preliminary understanding of the leaching system immersed mine bacterial populations, this study culture method to explore the leaching system, forty bioleaching bacteria isolated, and determination of the of Fe2 oxidation rate of fourteen . Thereafter, the selection of one of the Fe2 higher oxidation rate three strains the YK12, YK9 YK14, the determination of the rate of leaching of copper sulfide ores, wherein the YK12 strain copper leaching rate of up to 58.82%. Fe2 oxidation rate of eight different strains of the 16S rRNA gene sequence analysis showed that they are acidophilic Thiobacillus thiooxidans strain In order to explore the composition and succession of bacterial leaching system, genomic DNA extraction, PCR amplification and DGGE method has been optimized. In extracting genomic by fractionated and concentrated to obtain bacterial cells, re-extraction of genomic DNA; hot start touchdown PCR amplification of 16S rRNA gene hypervariable region fragment; in DGGE aspect, the obtained in the PCR amplification, using electrophoresis conditions : polyacrylamide gel concentration was 6%, and a gradient of 30% -50% denaturing gel, and voltage is 100V, the electrophoresis time of 9 hours. Optimized using the above method, shake flask cultures of copper sulphide ore and nickel sulfide ore, agitation leaching and column leaching three leaching system bacterial population structure DGGE analysis. Copper sulfide ores the column leaching Samples DGGE profile obtained six different bands, and the shake flask culture and agitation leaching obtain only one and three strip. Cloning, sequencing and phylogenetic analysis of all bands, they are strains of A. ferrooxidans 16S rRNA gene sequence with the highest homology. Combined DGGE analysis and leaching rate results show that the system of three leaching, bioleaching bacteria populations are acidophilic Thiobacillus thiooxidans. Acidophilic Thiobacillus ferrooxidans populations column leaching system, composed of a relatively complex, there are more obvious flora succession phenomenon, but the lower rate of leaching. Agitation leaching and shake flask cultures acidophilic Thiobacillus ferrooxidans species composition in the leaching system is simple, the leaching rate of growth in the leach rate, leaching system changes with the amount of bacterial growth has obvious relevance. This paper use by DGGE the three leaching system immersed ore bacterial artificial environment of the community to explore, contribute to further understanding of the leaching system immersed in the mineral composition of the bacteria and succession, for the control and optimization of the leaching conditions and improve the leaching rate of the foundation.
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