A Slow-Release Substrate Stimulates Groundwater Microbial Communities for Long-Term in Situ Cr(VI) Reduction

Journal Article · Thu Apr 02 04:00:00 EDT 2015 · Environmental Science and Technology

DOI:https://doi.org/10.1021/acs.est.5b00024· OSTI ID:1470905

Zhang, Ping ^[1]; Van Nostrand, Joy D. ^[1]; He, Zhili ^[1]; Chakraborty, Romy ^[2]; Deng, Ye ^[3]; Curtis, Daniel ^[1]; Fields, Matthew W. ^[4]; Hazen, Terry C. ^[5]; Arkin, Adam P. ^[2]; Zhou, Jizhong ^[6]

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1. Univ. of Oklahoma, Norman, OK (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
3. Univ. of Oklahoma, Norman, OK (United States); Chinese Academy of Sciences (CAS), Beijing (China)
4. Montana State Univ., Bozeman, MT (United States)
5. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
6. Univ. of Oklahoma, Norman, OK (United States) ; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsinghua University, Beijing (China)

Cr(VI) is a widespread environmental contaminant that is highly toxic and soluble. Previous work indicated that a one-time amendment of polylactate hydrogen-release compound (HRC) reduced groundwater Cr(VI) concentrations for >3.5 years at a contaminated aquifer; however, microbial communities responsible for Cr(VI) reduction are poorly understood. In this work, we hypothesized that HRC amendment would significantly change the composition and structure of groundwater microbial communities, and that the abundance of key functional genes involved in HRC degradation and electron acceptor reduction would increase long-term in response to this slowly degrading complex substrate. To test these hypotheses, groundwater microbial communities were monitored after HRC amendment for >1 year using a comprehensive functional gene microarray. The results showed that the overall functional composition and structure of groundwater microbial communities underwent sequential shifts after HRC amendment. Particularly, the abundance of functional genes involved in acetate oxidation, denitrification, dissimilatory nitrate reduction, metal reduction, and sulfate reduction significantly increased. The overall community dynamics was significantly correlated with changes in groundwater concentrations of microbial biomass, acetate, NO₃^-, Cr(VI), Fe(II) and SO₄^2-. In conclusion, our results suggest that HRC amendment primarily stimulated key functional processes associated with HRC degradation and reduction of multiple electron acceptors in the aquifer toward long-term Cr(VI) reduction.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
• DOE Contract Number: AC05-00OR22725; AC02-05CH11231
• OSTI ID: 1470905
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 21 Vol. 49; ISSN 0013-936X
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
59 BASIC BIOLOGICAL SCIENCES