Development and characterization of DehaloR 2, a novel anaerobic microbial consortium performing rapid dechlorination of TCE to ethene

Michal Ziv-El, Anca Delgado, Ying Yao, Dae Wook Kang, Katherine G. Nelson, Rolf Halden, Rosa Krajmalnik-Brown

Research output: Contribution to journalArticle

35 Scopus citations


A novel anaerobic consortium, named DehaloR 2, that performs rapid and complete reductive dechlorination of trichloroethene (TCE) to ethene is described. R 2 was developed from estuarine sediment from the Back River of the Chesapeake Bay and has been stably maintained in the laboratory for over 2 years. Initial sediment microcosms showed incomplete reduction of TCE to DCE with a ratio of trans- to cis- isomers of 1.67. However, complete reduction to ethene was achieved within 10 days after transfer of the consortium to sediment-free media and was accompanied by a shift to cis-DCE as the prevailing intermediate metabolite. The microbial community shifted from dominance of the Proteobacterial phylum in the sediment to Firmicutes and Chloroflexi in R 2, containing the genera Acetobacterium, Clostridium, and the dechlorinators Dehalococcoides. Also present were Spirochaetes, possible acetogens, and Geobacter which encompass previously described dechlorinators. Rates of TCE to ethene reductive dechlorination reached 2.83 mM Cl- d-1 in batch bottles with a Dehalococcoides sp. density of 1.54E+11 gene copies per liter, comparing favorably to other enrichment cultures described in the literature and identifying R 2 as a promising consortium for use in bioremediation of chlorinated ethene-impacted environments.

Original languageEnglish (US)
Pages (from-to)1063-1071
Number of pages9
JournalApplied Microbiology and Biotechnology
Issue number5
StatePublished - Dec 2011



  • Chlorinated ethenes
  • Dehalococcoides
  • Reductive dechlorination
  • Sediment microorganisms

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology

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