Multiple metal-resistant bacteria and fungi from acidic copper mine tailings of Xinjiang, China

The microbiology of mining environments has become a research topic of great importance. The present study reports on six bacterial and three fungal isolates which were characterized on a molecular basis. The phylogenetic analysis distributed the bacterial isolates into six groups in which groups A, B and C belonged to Bacillus beringensis, Bacillus sp. and Bacillus megaterium, respectively, while groups D, E and F constituted strains of Pseudomonas putida, Acidothiobacillus sp. and Kocuria sp., respectively. Fungi isolated belonged to the genera Aspergillus, Fusarium and Hypocrea. These isolates showed metal resistances to six heavy metals: Cu, Cr, Pb, Cd, Sb and Ni. For the bacteria, the minimum inhibitory concentrations (MICs) of these metals were in the range of 1-11 mM, whereas for fungi, the MIC was in the range of 5-20 mM. The multiple heavy metal-resistant bacterial species may be further screened for application to bioremediation.