Disentangling effects of temperature on microbial community and copper extraction in column bioleaching of low grade copper sulfide.

The lack of knowledge about responses of microbial community to temperature in copper sulfide bioleaching, and subsequent effects on copper extraction hampered understanding of how to improve bioleaching efficiency. This study presents first detailed quantitative data on microbial diversity and dynamics during bioleaching of low grade copper sulfide at different temperatures. The results demonstrate that temperature had significant effects on microbial community and copper extraction. The microbial structures on the ore surfaces were independent of communities in the leachates. Different species dominated the communities at different temperatures and portions of laboratory scale heap column. Moderate thermophiles rather than extreme thermophiles dominated the communities at 65 °C. The height of ore bed was sufficient to affect microbial communities at 30 °C and 65 °C. Sulfur-oxidizers were very important to improve copper extraction. High microbial diversity also were beneficial to enhance copper extraction within a certain temperature range in the final stage.