GeoChip-based analysis of functional microbial communities in a bioreduced uranium-contaminated aquifer during reoxidation by oxygen

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Environmental Microbiology

DOI:https://doi.org/10.1111/j.1462-2920.2009.01986.x· OSTI ID:973686

Van Nostrand, J D; Wu, W -M; Wu, L; Deng, Y; Carley, J; Carroll, S; He, Z; Gu, B; Luo, J; Criddle, C S; Watson, D B; Jardine, P M; Tiedje, J M; Hazen, T C; Zhou, J

A pilot-scale system was established for in situ biostimulation of U(VI) reduction by ethanol addition at the US Department of Energy's (DOE's) Field Research Center (Oak Ridge, TN). After achieving U(VI) reduction, stability of the bioreduced U(IV) was evaluated under conditions of (i) resting (no ethanol injection), (ii) reoxidation by introducing dissolved oxygen (DO), and (iii) reinjection of ethanol. GeoChip, a functional gene array with probes for N, S and C cycling, metal resistance and contaminant degradation genes, was used for monitoring groundwater microbial communities. High diversity of all major functional groups was observed during all experimental phases. The microbial community was extremely responsive to ethanol, showing a substantial change in community structure with increased gene number and diversity after ethanol injections resumed. While gene numbers showed considerable variations, the relative abundance (i.e. percentage of each gene category) of most gene groups changed little. During the reoxidation period, U(VI) increased, suggesting reoxidation of reduced U(IV). However, when introduction of DO was stopped, U(VI) reduction resumed and returned to pre-reoxidation levels. These findings suggest that the community in this system can be stimulated and that the ability to reduce U(VI) can be maintained by the addition of electron donors. This biostimulation approach may potentially offer an effective means for the bioremediation of U(VI)-contaminated sites.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Earth Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 973686
• Report Number(s): LBNL-2636E
• Journal Information: Environmental Microbiology, Journal Name: Environmental Microbiology Journal Issue: 10 Vol. 11; ISSN 1462-2912
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
ABUNDANCE
AQUIFERS
BINDING ENERGY
BIOREMEDIATION
COMMUNITIES
DISSOLVED GASES
ELECTRONS
ETHANOL
FUNCTIONALS
GENES
MONITORING
OXYGEN
PROBES
REINJECTION
STABILITY
VALENCE