Cryogenic soil coring reveals coexistence of aerobic and anaerobic vinyl chloride degrading bacteria in a chlorinated ethene contaminated aquifer

Patrick M. Richards, Yi Liang, Richard L. Johnson, Timothy E. Mattes

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Vinyl chloride (VC) is a common groundwater contaminant and known human carcinogen. Three major bacterial guilds are known to participate in VC biodegradation: aerobic etheneotrophs and methanotrophs, and anaerobic organohalide-respiring VC-dechlorinators. We investigated the spatial relationships between functional genes representing these three groups of bacteria (as determined by qPCR) with chlorinated ethene concentrations in a surficial aquifer at a contaminated site. We used cryogenic soil coring to collect high-resolution aquifer sediment samples and to preserve sample geochemistry and nucleic acids under field conditions. All samples appeared to be anaerobic (i.e., contained little to no dissolved oxygen). VC biodegradation associated functional genes from etheneotrophs (etnC and/or etnE), methanotrophs (mmoX and/or pmoA), and anaerobic VC-dechlorinators (bvcA and/or vcrA) coexisted in 48% of the samples. Transcripts of etnC/etnE and bvcA/vcrA were quantified in contemporaneous groundwater samples, indicating co-located gene expression. Functional genes from etheneotrophs and anaerobic VC-dechlorinators were correlated to VC concentrations in the lower surficial aquifer (p < 0.05). Methanotroph functional genes were not correlated to VC concentrations. Cryogenic soil coring proved to be a powerful tool for capturing high-spatial resolution trends in geochemical and nucleic acid data in aquifer sediments. We conclude that both aerobic etheneotrophs and anaerobic VC-dechlorinators may play a significant role in VC biodegradation in aquifers that have little dissolved oxygen.

Original languageEnglish (US)
Pages (from-to)281-291
Number of pages11
JournalWater Research
Volume157
DOIs
StatePublished - Jun 15 2019

Keywords

  • Anaerobic VC-Dechlorinator
  • Aquifer sediments
  • Chlorinated solvents
  • Cryogenic coring
  • Etheneotrophs
  • Methanotrophs
  • Vinyl chloride

ASJC Scopus subject areas

  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

Fingerprint Dive into the research topics of 'Cryogenic soil coring reveals coexistence of aerobic and anaerobic vinyl chloride degrading bacteria in a chlorinated ethene contaminated aquifer'. Together they form a unique fingerprint.

  • Cite this