Title Molecular Analysis of Prokaryotic Diversity in the Deep Subsurface of the Former Homestake Gold Mine, South Dakota, USA
Author Gurdeep Rastogi1, Larry D. Stetler2, Brent M. Peyton3, and Rajesh K. Sani1*
Address 1Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA, 2Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA, 3Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT 59717, USA
Bibliography Journal of Microbiology, 47(4),371-384, 2009,
Key Words Homestake, DUSEL, gold mine, microbial diversity
Abstract A culture-independent molecular phylogenetic analysis was carried out to study the prokaryotic diversity in two soil samples collected from the subsurface (1.34 km depth) of the former Homestake gold mine, Lead, South Dakota, USA at two sites, the Ross shaft and number 6 Winze. Microbial community analyses were performed by cloning and sequencing of 16S rRNA genes retrieved directly from soil samples. Geochemical characterization of soils revealed high amount of toxic metals such as As, Cd, Co, Cr, Cu, Ni, Pb, Zn, and U at both the sites. Phylogenetic analyses showed that soil samples were predominantly composed of phylotypes related to phylum Proteobacteria. Other phyla detected in libraries were Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Chlorobi, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Verrucomicrobia, and candidate divisions OP10 and TM7. The majority (>95%) of the phylotypes retrieved in the libraries were most closely related to environmental sequences from yet-uncultured bacteria representing a hitherto unidentified diversity. The archaeal communities at both the sites exhibited lower diversity and were most closely affiliated to uncultivated species within the Crenarchaeota. Results showed the existence of diverse microbial populations in deep subsurface environment of the Homestake gold mine. Statistical analyses demonstrated that each site harbored phylogenetically distinct microbial populations that were more diverse at Ross site compare to winze site.