RRC ID 19085
Author Green SJ, Prakash O, Jasrotia P, Overholt WA, Cardenas E, Hubbard D, Tiedje JM, Watson DB, Schadt CW, Brooks SC, Kostka JE.
Title Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site.
Journal Appl Environ Microbiol
Abstract The effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of rRNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure and that denitrifying bacteria from the genus Rhodanobacter (class Gammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower-pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as the concentration of nitrogen species, oxygen level, and sampling season, did not appear to strongly influence the distribution of Rhodanobacter bacteria. The results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.
Volume 78(4)
Pages 1039-47
Published 2012-2-1
DOI 10.1128/AEM.06435-11
PII AEM.06435-11
PMID 22179233
PMC PMC3273022
MeSH Biota* DNA, Bacterial / genetics Denitrification Groundwater / chemistry Groundwater / microbiology* Hydrogen-Ion Concentration Metagenome Metagenomics / methods Nitrogen / analysis Oxygen / analysis RNA, Bacterial / genetics Radioactive Waste Soil Pollutants, Radioactive / metabolism* Xanthomonadaceae / classification* Xanthomonadaceae / isolation & purification* Xanthomonadaceae / metabolism
IF 4.016
Times Cited 87
General Microbes JCM 17641 JCM 17642