2009 microbial community

The Zijin heap bioleaching plant began operation near the end of 2005, and over 4 years of operation, concerns rose about the migration of acidophiles outside of the heap due to the proximity of the Ting River. In this study, 53 soil samples and 58 liquid samples were collected, and the biogeographical distribution of acidophiles around the Zijin heap bioleaching plant was investigated using clone libraries. Four key acidophiles, including the genera of Acidithiobacillus, Leptospirillum, Ferroplasma and Sulfobacillus were assayed by real-time PCR, and the physicochemical characteristics of the samples were also analyzed. The results grouped 2654 sequences from 6 clone libraries into 611 OTUs with a distance level of 3%. All of the 611 OTUs belonged to 127 genera; Acidithiobacillus, Leptospirillum, Undibacterium, Gp1 and Gp2 were the five most represented genera. The results of shared species analysis detected only one bioleaching microorganism (Acidithiobacillus) in the liquid samples, and no bioleaching microorganisms were detected in the other surrounding environments. The results of real-time PCR showed that there were two key species in several of the solid samples (mainly concentrated in the zone 30 m outside of the heap-bioleaching system) and most of the liquid samples. The order of the bioleaching microorganisms from more to less was Leptospirillum, Acidithiobacillus, no Sulfobacillus or Ferroplasma was detected. The physicochemical analysis indicated there were some correlation between the physicochemical index and the presence of acidophiles.