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Acidophilic Thiobacillus ferrooxidans can oxidize ferrous iron and reduced sulfur (Acidithiobacillus ferrooxidans, referred A.ferrooxidans) the solution dip role of the metal ion, is a bacteria play a major role in the process of leaching. The paper selected ancient copper mine area Tonglushan stone mouth acidic mine water, filtering the high activity of iron-oxidizing bacteria, 16S rDNA molecular identification, physiological and biochemical characteristics and heavy metal resistance, and use of the strains of Yunnan, Anhui, Daye low grade oxide - sulfide mixed copper ore and other places shake flask leaching tests. Main results are as follows: 1 in the initial enrichment experiments, a total of eight for iron oxidizing bacteria, and further subjected to secondary screening, the oxidation activity of the highest strain SY. Amplified 16S rDNA of strain SY cloning, sequencing and homology analysis and sequence alignment found with Thiobacillus thiooxidans strains (DQ 062116.1) most similar strain was identified as Thiobacillus bacilli. Determination of physiological and biochemical properties show that the strain SY optimum growth temperature of 30 ° C. The optimum pH value of 2.0, inoculum size complete oxidation of ferrous ions have little effect. 4 strain SY Cu 2 , Cd 2 Ni 2 , Zn 2 and other heavy metal ion resistance The minimum inhibitory concentration (MIC) were 300,350,700 and 800 mmol / L, showing a high resistance to a variety of heavy metal ions. The strain after about a month of domestication, 400 mmol / LCu 2 ion environment, within 48 hours of complete oxidation of ferrous ions. 5 20 days. Strain SY oxidation of Hubei Daye, Lijiang, Yunnan and Anhui Zongyang other places - sulfide mixed low-grade copper ore leaching experiments show that bacterial leaching acid leaching of Cu 2 recovery rate of nearly 30%, indicating that the strains in the leaching of sulphide ore has good application prospects. Bioleaching process, strain SY Daye in Hubei, Anhui Zongyang, Lijiang, Yunnan and other places of the kind of low-grade ore leaching rate were 84.28%, 74.38%, and 33.31%, respectively. Thiobacillus ferrooxidans strains used in the literature, strain SY variety of heavy metal show high resistance, very much in line with the requirements of multi-metal complex ore leaching, showed good application value. The SY bacteria Daye mixed copper ore leaching results show that the indigenous strains isolated in the local ore bioleaching shows great advantages.
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