关键词: 黄铜矿, 优势菌群, 生物浸出, 16S rDNA, 序列分析, 嗜酸氧化亚铁硫杆菌

Abstract: In order to find out the reaction mechanism of bacteria with chalcopyrite, the dominant bacteria in a bioleaching system of low-grade copper sulphide ore consisting mainly of chalcopyrite were investigated. By using a 9K culture medium, 14 pure strains of mesophiles were isolated from leaching pulp of the ore. Copper leaching rates for these pure strains were all lower than those before isolation, indicating that there exists a synergistic effect among these strains of the domestic bacteria in the bioleaching process of the ore. By the sequence analysis of 16S rDNA, strains YK8, YK12 and YK14, which were randomly sampled from the 14 strains, were highly relative to Acidithiobacillus ferrooxidans, with 99% sequence similarity, though they were very different in oxidation ability from each other. The three strains were identified as the species of Acidithiobacillus ferrooxidans, exhibiting the diversity of singleness of the bacterium community. The fact that the bioleaching system was dominated by the species of Acidithiobacillus ferrooxidans indicates that the mechanism of bacterial oxidation is mainly direct reaction. There were marked differences in Fe2+ oxidation rate of various pure strains and notable changes in copper leaching rate for various bacteria induced by different culture media containing different energy sources.

Key words: chalcopyrite ore, dominant bacteria, bioleachin, 16S rDNA, sequence analysis, Acidithiobacillus ferrooxidans