Variation in energy metabolism structure of microbial community during bioleaching chalcopyrites with different iron-sulfur ratios

不同铁硫比的黄铜矿浸出过程中微生物群落能量代谢结构的变化

The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum and Acidithiobacillus thiooxidans)was used to leach three kinds of chalcopyrites with different iron-sulfur ratios.After 36 d of leaching,the chalcopyrite with iron-sulfur ratio of about 1:1 achieved the highest copper extraction(69.62%).In the early stage,iron oxidizing bacteria predominated,and the expression of rus and rio was 8 times higher than that in the late stage.In the late stage,sulfur oxidizing bacteria predominated,and the expression of tetH and HdrAB was 4 times higher than that in the early stage.Furthermore,the three bioleaching systems above were added with elemental sulfur(3 g/L);the chalcopyrite with iron-sulfur ratio of about 2:1 achieved the highest copper extraction(80.63%).The results suggest that the energy metabolism structure of the microbial community could be changed by changing the iron-sulfur ratio during the leaching process for improving the leaching efficiency of chalcopyrite.

微生物群落的能量代谢结构在生物湿法冶金过程中起着重要作用。本文采用由嗜酸氧化亚铁硫杆菌、嗜铁钩端螺旋菌和嗜酸氧化硫硫杆菌三种菌株组成的人工微生物群落对三种不同铁硫比的黄铜矿进行浸出。经过36 d的浸出,铁硫比约为1:1的黄铜矿的铜浸出率最高(69.62%)。前期以铁氧化菌为主,rus和rio的表达量比后期高8倍。后期以硫氧化菌为主,tetH和HdrAB的表达量比前期高4倍。此外,上述三个生物浸出系统添加元素硫(3 g/L),且铁硫比约为2:1的黄铜矿的铜浸出率最高(80.63%)。结果表明,在浸出过程中改变铁硫比可以改变微生物群落的能量代谢结构,从而提高黄铜矿的浸出效率。