AUTHOR=Hemme Christopher L. , Tu Qichao , Shi Zhou , Qin Yujia , Gao Weimin , Deng Ye , Nostrand Joy D. Van , Wu Liyou , He Zhili , Chain Patrick S. G. , Tringe Susannah G. , Fields Matthew W. , Rubin Edward M. , Tiedje James M. , Hazen Terry C. , Arkin Adam P. , Zhou Jizhong TITLE=Comparative metagenomics reveals impact of contaminants on groundwater microbiomes JOURNAL=Frontiers in Microbiology VOLUME=6 YEAR=2015 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.01205 DOI=10.3389/fmicb.2015.01205 ISSN=1664-302X ABSTRACT=

To understand patterns of geochemical cycling in pristine versus contaminated groundwater ecosystems, pristine shallow groundwater (FW301) and contaminated groundwater (FW106) samples from the Oak Ridge Integrated Field Research Center (OR-IFRC) were sequenced and compared to each other to determine phylogenetic and metabolic difference between the communities. Proteobacteria (e.g., Burkholderia, Pseudomonas) are the most abundant lineages in the pristine community, though a significant proportion ( >55%) of the community is composed of poorly characterized low abundance (individually <1%) lineages. The phylogenetic diversity of the pristine community contributed to a broader diversity of metabolic networks than the contaminated community. In addition, the pristine community encodes redundant and mostly complete geochemical cycles distributed over multiple lineages and appears capable of a wide range of metabolic activities. In contrast, many geochemical cycles in the contaminated community appear truncated or minimized due to decreased biodiversity and dominance by Rhodanobacter populations capable of surviving the combination of stresses at the site. These results indicate that the pristine site contains more robust and encodes more functional redundancy than the stressed community, which contributes to more efficient nutrient cycling and adaptability than the stressed community.