Journal
MICROBIAL ECOLOGY
Volume 75, Issue 4, Pages 941-953Publisher
SPRINGER
DOI: 10.1007/s00248-017-1100-1
Keywords
Contaminated aquifer; Anaerobic benzene degradation; Community shift; Compound-specific stable isotope analysis
Categories
Ask authors/readers for more resources
Benzene mineralization under nitrate-reducing conditions was successfully established in an on-site reactor continuously fed with nitrate and sulfidic, benzene-containing groundwater extracted from a contaminated aquifer. Filling material from the reactor columns was used to set up anoxic enrichment cultures in mineral medium with benzene as electron donor and sole organic carbon source and nitrate as electron acceptor. Benzene degradation characteristics and community composition under nitrate-reducing conditions were monitored and compared to those of a well-investigated benzene-mineralizing consortium enriched from the same column system under sulfate-reducing conditions. The nitrate-reducing cultures degraded benzene at a rate of 10.1 +/- 1.7 mu M d(-1), accompanied by simultaneous reduction of nitrate to nitrite. The previously studied sulfate-reducing culture degraded benzene at similar rates. Carbon and hydrogen stable isotope enrichment factors determined for nitrate-dependent benzene degradation differed significantly from those of the sulfate-reducing culture (Lambda(H/C nitrate) = 12 +/- 3 compared to Lambda(H/C sulfate) = 28 +/- 3), indicating different benzene activation mechanisms under the two conditions. The nitrate-reducing community was mainly composed of Betaproteobacteria, Ignavibacteria, and Anaerolineae. Azoarcus and a phylotype related to clone Dok59 (Rhodocyclaceae) were the dominant genera, indicating an involvement in nitrate-dependent benzene degradation. The primary benzene degrader of the sulfate-reducing consortium, a phylotype belonging to the Peptococcaceae, was absent in the nitrate-reducing consortium.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available