Bioleaching of copper sulfides using mixed microorganisms and its community structure succession in the presence of seawater.

The bacterial diversity and dynamics in the leaching solution were analyzed during bioleaching of low-grade copper sulfide ore in the presence of seawater in this study. The results indicated a promoting response of appropriate-proportion seawater to bioleaching with improved copper recoveries. A maximum of 84.70% copper recovery was obtained in the presence of 20.00% seawater in contrast to only 72.49% in its absence. The experiments verified that seawater owned a great influence on Attached bacteria and bacterial species. 16S rDNA analysis illustrated that bacterial species decreased distinctly in the presence of seawater. Little difference between blank sample (no seawater) and sample adding 20.00% seawater was indicated by beta diversity index. Bacteria (including Acidithiobacillus ferrooxidans, Sphingomonas leidyi and Lactobacillus acetotolerans) were influenced significantly after adding seawater. Acidithiobacillus ferrooxidans accounted for the highest proportion of the community whether seawater was added or not during bioleaching.