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Title: Dynamic Succession of Groundwater Sulfate-Reducing Communities during Prolonged Reduction of Uranium in a Contaminated Aquifer

To further understand the diversity and dynamics of SRB in response to substrate amendment, we sequenced genes coding for the dissimilatory sulfite reductase (dsrA) in groundwater samples collected after an emulsified vegetable oil (EVO) amendment, which sustained U(VI)-reducing conditions for one year in a fast-flowing aquifer. EVO amendment significantly altered the composition of groundwater SRB communities. Sequences having no closely related-described species dominated (80%) the indigenous SRB communities in nonamended wells. After EVO amendment, Desulfococcus, Desulfobacterium, and Desulfovibrio, known for long-chain-fatty-acid, short-chain-fatty-acid and H 2 oxidation and U(VI) reduction, became dominant accounting for 7 ± 2%, 21 ± 8%, and 55 ± 8% of the SRB communities, respectively. Succession of these SRB at different bioactivity stages based on redox substrates/products (acetate, SO 4 –2, U(VI), NO 3 , Fe(II), and Mn(II)) was observed. Desulfovibrio and Desulfococcus dominated SRB communities at 4–31 days, whereas Desulfobacterium became dominant at 80–140 days. By the end of the experiment (day 269), the abundance of these SRB decreased but the overall diversity of groundwater SRB was still higher than non-EVO controls. Up to 62% of the SRB community changes could be explained by groundwater geochemical variables, including those redox substrates/products. A significant ( P <more » 0.001) correlation was observed between groundwater U(VI) concentrations and Desulfovibrio abundance. Lastly, our results showed that the members of SRB and their dynamics were correlated significantly with slow EVO biodegradation, electron donor production and maintenance of U(VI)-reducing conditions in the aquifer.« less
Authors:
ORCiD logo [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [2] ;  [4] ; ORCiD logo [5] ; ORCiD logo [6] ; ORCiD logo [7] ; ORCiD logo [8] ;  [9] ;  [10] ;  [11]
  1. Univ. of Oklahoma, Norman, OK (United States); Univ. of Texas MD Anderson Cancer Center, Houston, TX (United States)
  2. Univ. of Oklahoma, Norman, OK (United States)
  3. Univ. of Oklahoma, Norman, OK (United States); Chinese Academy of Sciences (CAS), Beijing (China)
  4. Univ. of Oklahoma, Norman, OK (United States); Zhejiang Univ., Zhejiang (China)
  5. Univ. of Oklahoma, Norman, OK (United States); Chinese Academy of Sciences, Nanjing (China)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  7. Montana State Univ., Bozeman, MT (United States)
  8. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  9. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  10. Univ. of Washington, Seattle, WA (United States)
  11. Univ. of Oklahoma, Norman, OK (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsinghua Univ., Beijing (China)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 51; Journal Issue: 7; Journal ID: ISSN 0013-936X
Publisher:
American Chemical Society (ACS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES
OSTI Identifier:
1394592