Genomic islands and their importance in metal resistance for biomining bacteria
Biomining extremophilic bacteria and archaea in general possess high Cu resistance that may be the result of having a wide repertoire of Cu-resistance determinants and other recently described properties. The genomic sequence of Acidithiobacillus ferrooxidans ATCC 53993 has all the Cu-resistance genes from A. fenooxidans ATCC 23270 that have been experimentally confirmed to be expressed in the presence of Cu, and are also 100％ identical between both strains. A. ferrooxidans ATCC 53993 possesses in its genome a region of around 160 Kb or genomic island (GI) which is absent in strain ATCC 23270. This GI contains amongst other genes, several ORFs coding for possible metal transporters and additional Cu-resistance determinants such as a putative CuATPase and a Cus system. As detected by qRT-PCR some of the genes exclusively present in strain ATCC 53993 were upregulated by its growth in the presence of Cu. Furthermore, when comparing the capacity of these two A. ferrooxidans strains (not previously adapted to Cu) to grow in the presence of Cu, strain ATCC 53993 had a much higher Cu resistance (200 mM) than that of ATCC 23270 strain (25 raM). This difference may be most likely explained by the presence of the additional putative metal resistance genes present in the GI of strain ATCC 53993. Therefore, the grounds for resistance to Cu of two strains of the same microorganism could underlie in slight differences in their genomes, which may lead to differences in their capacities to adapt in a mineral environment. This knowledge is highly relevant, since it will provide key information to the mining industry that could be used to select the more fit members of the bioleaching community to attain more efficient industrial biomining processes.
genomic islands copper resistance Acidithiobacillus ferrooxidans 23270 Acidithiobacillus ferrooxidans 53993
Luis H. Orellana Claudio A. Navarro Carlos A. Jerez
Laboratory of Molecular Microbiology and Biotechnology, Department of Biology and Millennium Institute for Cell Dynamics and Biotechnology, Faculty of Sciences, University of Chile, Santiago, Chile
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
321-326
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）