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

Abstract

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.