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Title: Characterization of the Deltaproteobacteria in Contaminated and Uncontaminated Surface Stream Sediments and Identification of Potential Mercury Methylators

Journal Article · · Aquatic Microbial Ecology
DOI:https://doi.org/10.3354/ame01563· OSTI ID:1038465

Microbial communities were examined in surface stream sediments at five contaminated sites and one control site near Oak Ridge, TN in order to identify bacteria that could be contributing to mercury methylation. The phylogenetic composition of the sediment bacterial community was examined over three quarterly sampling periods (36 samples) using 16s rRNA pyrosequencing. Only 3064 sequences (0.85 % of the total community) were identified as Deltaproteobacteria by the RDP classifier at the 99% confidence threshold. Constrained ordination techniques indicated significant positive correlations between Desulfobulbus spp., Desulfonema spp. and Desulfobacca spp. and methyl mercury concentrations in the contaminated sites. On the contrary, the distribution of organisms related to Byssovorax was significantly correlated to inorganic carbon, nitrate and uranium concentrations. Overall, the abundance and richness of Deltaproteobacteria sequences were higher in the sediments of the site, while the majority of the members present at the contaminated sites were either known metal reducers/methylators or metal tolerant species.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
1038465
Journal Information:
Aquatic Microbial Ecology, Vol. 66, Issue 3; ISSN 0948--3055
Country of Publication:
United States
Language:
English