Stressful Living in Contaminated Groundwater
Microorganisms are the primary drivers of key subsurface geochemical processes but we only have limited understanding of the composition and function of the microbial communities involved. “Metagenomic” sequencing is providing insights into the metabolic capabilities of these microbial communities and microbial adaptations to environmental changes. A multi-institutional team from the University of Oklahoma, Oak Ridge and Lawrence Berkeley National Laboratories, and the DOE Joint Genome Institute has now sequenced microbial community DNA isolated from groundwater at a site with low pH and high levels of uranium, technetium, nitrate, and organic solvents. The analysis reveals a significant reduction in microbial diversity from background and an overabundance of genes that confer tolerance for nitrate, heavy metals, and organic solvents. In addition, the overabundance of genes for DNA recombination and repair suggests the presence of lateral gene transfer induced by exposure to extreme environmental conditions. These results expand our understanding of how microbial communities adapt to and influence the fate of environmental contaminants.
Hemme, C.L., Y. Deng, T.J. Gentry, M.W. Fields, L. Wu, S. Barua, K. Barry, S.G. Tringe, D.B. Watson, Z. He, T.C. Hazen, J.M. Tiedje, E.M. Rubin, and J. Zhou. 2010. “Metagenomic Insights into Evolution of a Heavy Metal-Contaminated Groundwater Microbial Community.” ISME Journal 4: 660-672.