Journal
AQUATIC MICROBIAL ECOLOGY
Volume 66, Issue 3, Pages 271-282Publisher
INTER-RESEARCH
DOI: 10.3354/ame01563
Keywords
Deltaproteobacteria; Mercury; Methylmercury; Stream sediments
Categories
Funding
- U.S. Department of Energy's Office of Science Biological and Environmental Research, Subsurface Biogeochemical Research program
- U.S. Department of Energy [DE-AC05-00OR22725]
Ask authors/readers for more resources
Microbial communities were examined in surface stream sediments at 5 contaminated sites and 1 control site near Oak Ridge, TN, USA, to identify bacteria that could be contributing to mercury (Hg) methylation. The phylogenetic composition of the sediment bacterial community was examined over 3 quarterly sampling periods (36 samples) using 16S rRNA gene pyrosequencing. Only 3064 sequences (0.85% of the total community) were identified as Deltaproteobacteria, the only group known to methylate Hg, using the Ribosomal Database Project classifier at the 99% confidence threshold. Constrained ordination techniques indicated statistically significant positive linear correlations between Desulfobulbus spp., Desulfonema spp. and Desulfobacca spp. and methyl-Hg concentrations at the Hg-contaminated sites. In contrast, the distribution of organisms related to Byssovorax spp. was significantly correlated to inorganic carbon, nitrate and uranium concentrations but not to Hg or methyl-Hg. Overall, the abundance and richness of Deltaproteobacteria sequences were higher in uncontaminated sediments, while the majority of the members present at the contaminated sites were either known potential metal-reducers/methylators or metal tolerant species. Given the abundance relative to other known Hg methylators and the association with methyl-Hg, Desulfobulbus spp. is considered a prime candidate for involvement in Hg methylation in these streams.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available