An Fe(II)-oxidizing consortium from Wudalianchi volcano spring in Northeast China for bioleaching of Cu and Ni from printed circuit boards (PCBs) with the dominance of Acidithiobacillus spp.

A Fe(II)-oxidizing microbial consortium BYQ was enriched from a spring that is rich in iron (38.57 mg/L) in Wudalianchi volcanic area in Northeast China. Its Fe(II) oxidation potential was evaluated under different conditions and the maximum Fe(II) oxidation rate achieved 1.29 g/L·h. The effectiveness of consortium BYQ on bioleaching performance indicated that simultaneous extraction of 89.09 and 68.52% of Cu and Ni from PCBs was achieved with the maximum leaching rates of 0.46 and 0.032 g/L·d, respectively. The microbial composition dynamic implied Acidithiobacillus spp. invariably dominated the community for more than 96% regardless of subculturing and bioleaching conditions. SEM, XRD and FT-IR detected the surface attack of PCBs and the releasing of Cu and Ni with jarosite formation as one of the minerals during bioleaching. The findings showed the high-efficiency Fe(II) oxidation and PCBs leaching of consortium BYQ, suggesting that the volcanic springs might be rich sources of microorganisms for biotechnological and industrial applications.