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BioMed Research International
Volume 2014, Article ID 787034, 11 pages
http://dx.doi.org/10.1155/2014/787034
Research Article

Cross-Comparison of Leaching Strains Isolated from Two Different Regions: Chambishi and Dexing Copper Mines

1School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China
2Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha 410083, China

Received 28 April 2014; Revised 23 July 2014; Accepted 12 August 2014; Published 16 November 2014

Academic Editor: Paula Loureiro Paulo

Copyright © 2014 Baba Ngom et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa) and Dexing copper mine (China, Asia), was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.