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

• Published in: Applied microbiology and biotechnology Vol. 92; no. 5; pp. 1063 - 1071
• Main Authors: Ziv-El, Michal, Delgado, Anca G, Yao, Ying, Kang, Dae-Wook, Nelson, Katherine G, Halden, Rolf U, Krajmalnik-Brown, Rosa
• Format: Journal Article
• Language: English
• Published: 01.02.2011
• Subjects: Acetobacterium; Clostridium; Dehalococcoides; Firmicutes; Geobacter; ANW, USA, Chesapeake Bay; USA, Maryland, Baltimore Cty., Back R
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-011-3388-y

A novel anaerobic consortium, named DehaloR arrow up , that performs rapid and complete reductive dechlorination of trichloroethene (TCE) to ethene is described. DehaloR arrow up 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 DehaloR arrow up , 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 super(-) d super(- 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 DehaloR arrow up as a promising consortium for use in bioremediation of chlorinated ethene-impacted environments.