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This content will become publicly available on March 5, 2019

Title: Microbial community structure with trends in methylation gene diversity and abundance in mercury-contaminated rice paddy soils in Guizhou, China

In this paper, paddy soils from mercury (Hg)-contaminated rice fields in Guizhou, China were studied with respect to total mercury (THg) and methylmercury (MeHg) concentrations as well as Bacterial and Archaeal community composition. Total Hg (0.25–990 μg g –1) and MeHg (1.3–30.5 ng g –1) varied between samples. Pyrosequencing (454 FLX) of the hypervariable v1–v3 regions of the 16S rRNA genes showed that Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Euryarchaeota, and Crenarchaeota were dominant in all samples. The Bacterial α-diversity was higher in samples with relatively Low THg and MeHg and decreased with increasing THg and MeHg concentrations. In contrast, Archaeal α-diversity increased with increasing of MeHg concentrations but did not correlate with changes in THg concentrations. Overall, the methylation gene hgcAB copy number increased with both increasing THg and MeHg concentrations. The microbial communities at High THg and High MeHg appear to be adapted by species that are both Hg resistant and carry hgcAB genes for MeHg production. The relatively high abundance of both sulfate-reducing δ- Proteobacteria and methanogenic Archaea, as well as their positive correlations with increasing THg and MeHg concentrations, suggests that these microorganisms are the primary Hg-methylators in the rice paddy soils in Guizhou, China.
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [1] ;  [4] ;  [4] ;  [4] ;  [3] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chinese Academy of Science, Guiyang (China)
  3. Univ. of Oklahoma, Norman, OK (United States)
  4. Chinese Academy of Science, Guiyang (China)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Environmental Science: Processes & Impacts
Additional Journal Information:
Journal Volume: 20; Journal Issue: 4; Journal ID: ISSN 2050-7887
Publisher:
Royal Society of Chemistry
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; Mercury; methylmercury; Hg-methylation; hgcAB; rice paddy soil; pyrosequencing
OSTI Identifier:
1435339