Journal article
Growth of Dehalococcoides spp. and increased abundance of reductive dehalogenase genes in anaerobic PCB-contaminated sediment microcosms
Environmental science and pollution research international, Vol.27(9), pp.8846-8858
03/2020
DOI: 10.1007/s11356-019-05571-7
PMCID: PMC6918016
PMID: 31209752
Abstract
Polychlorinated biphenyls (PCBs) contaminate 19% of US Superfund sites and represent a serious risk to human and environmental health. One promising strategy to remediate PCB-contaminated sediments utilizes organohalide-respiring bacteria (OHRB) that dechlorinate PCBs.However, functional genes that act as biomarkers for PCB dechlorination processes (i.e., reductive dehalogenase genes) are poorly understood. Here, we developed anaerobic sediment microcosms that harbor an OHRB community dominated by the genus Dehalococcoides. During the 430-day microcosm incubation, Dehalococcoides 16S rRNA sequences increased two orders of magnitude to 10
copies/g of sediment, and at the same time, PCB118 decreased by as much as 70%. In addition, the OHRB community dechlorinated a range of penta- and tetra-chlorinated PCB congeners including PCBs 66, 70 + 74 + 76, 95, 90 + 101, and PCB110 without exogenous electron donor. We quantified candidate reductive dehalogenase (RDase) genes over a 430-day incubation period and found rd14, a reductive dehalogenase that belongs to Dehalococcoides mccartyi strain CG5, was enriched to 10
copies/g of sediment. At the same time, pcbA5 was enriched to only 10
copies/g of sediment. A survey for additional RDase genes revealed sequences similar to strain CG5's rd4 and rd8. In addition to demonstrating the PCB dechlorination potential of native microbial communities in contaminated freshwater sediments, our results suggest candidate functional genes with previously unexplored potential could serve as biomarkers of PCB dechlorination processes.
Details
- Title: Subtitle
- Growth of Dehalococcoides spp. and increased abundance of reductive dehalogenase genes in anaerobic PCB-contaminated sediment microcosms
- Creators
- Jessica M Ewald - Department of Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, 52242, USAShelby V Humes - Department of Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, 52242, USAAndres Martinez - Department of Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, 52242, USAJerald L Schnoor - Department of Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, 52242, USATimothy E Mattes - Department of Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, 52242, USA. tim-mattes@uiowa.edu
- Resource Type
- Journal article
- Publication Details
- Environmental science and pollution research international, Vol.27(9), pp.8846-8858
- DOI
- 10.1007/s11356-019-05571-7
- PMID
- 31209752
- PMCID
- PMC6918016
- NLM abbreviation
- Environ Sci Pollut Res Int
- ISSN
- 1614-7499
- eISSN
- 1614-7499
- Publisher
- Germany
- Grant note
- P42 ES013661 / NIEHS NIH HHS NIH P42ES013661 / National Institute of Environmental Health Sciences (US)
- Language
- English
- Date published
- 03/2020
- Academic Unit
- Civil and Environmental Engineering; Occupational and Environmental Health; IIHR--Hydroscience and Engineering; Iowa Superfund Research Program
- Record Identifier
- 9983997422402771
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