skip to main content


Title: Temporal Dynamics of In-Field Bioreactor Populations Reflect the Groundwater System and Respond Predictably to Perturbation

Temporal variability complicates testing the influences of environmental variability on microbial community structure and thus function. An in-field bioreactor system was developed to assess oxic versus anoxic manipulations on in-situ groundwater communities. Each sample was sequenced (16S SSU rRNA genes, average 10,000 reads) and biogeochemical parameters monitored by quantifying 53 metals, 12 organic acids, 14 anions and 3 sugars. Changes in dissolved oxygen (DO), pH, and other variables were similar across bioreactors. Sequencing revealed a complex community that fluctuated in-step with the groundwater community, and responded to DO. This also directly influenced the pH and so the biotic impacts of DO and pH shifts are correlated. A null model demonstrated that bioreactor communities were driven in part by experimental conditions but also by stochastic variability and did not accurately capture alterations in diversity during perturbations. We identified two groups of abundant OTUs important to this system; one was abundant in high DO and pH and contained heterotrophs and oxidizers of iron, nitrite, and ammonium, whereas the other was abundant in low DO with the capability to reduce nitrate. In-field bioreactors are a powerful tool for capturing natural microbial community responses to alterations in geochemical factors beyond the bulk phase.
 [1] ;  [2] ;  [1] ; ORCiD logo [3] ;  [1] ;  [1] ;  [4] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [4] ;  [4] ; ORCiD logo [5] ;  [6] ;  [6] ; ORCiD logo [1] ; ORCiD logo [7] ;  [8] more »;  [9] ;  [5] ;  [6] ;  [4] ;  [8] ; ORCiD logo [4] « less
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Johns Hopkins Univ., Baltimore, MD (United States)
  3. Colorado State Univ., Fort Collins, CO (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  5. Univ. of Oklahoma, Norman, OK (United States)
  6. Univ. of Georgia, Athens, GA (United States)
  7. Montana State Univ., Bozeman, MT (United States)
  8. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  9. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 51; Journal Issue: 5; Journal ID: ISSN 0013-936X
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
59 BASIC BIOLOGICAL SCIENCES; 54 ENVIRONMENTAL SCIENCES; Bioreactor; Microbial Community; Groundwater
OSTI Identifier: