Growth of Dehalococcoides Strains with Chlorophenols as Electron Acceptors
- 22 February 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 41 (7), 2318-2323
- https://doi.org/10.1021/es062076m
Abstract
Dehalococcoides strains reductively dechlorinate a wide variety of halogenated compounds including chlorinated benzenes, biphenyls, naphthalenes, dioxins, and ethenes. Recent genome sequencing of the two Dehalococcoides strains CBDB1 and 195 revealed the presence of 32 and 18 reductive dehalogenase homologous genes, respectively, and therefore suggested an even higher dechlorinating potential than previously anticipated. Here, we demonstrate reductive dehalogenation of chlorophenol congeners by Dehalococcoides strains CBDB1 and 195. Strain CBDB1 completely converted 2,3-dichlorophenol, all six trichlorophenols, all three tetrachlorophenols, and pentachlorophenol to lower chlorinated phenols. Observed dechlorination rates in batch cultures with cell numbers of 107 mL-1 amounted up to 35 μM day-1. Chlorophenols were preferentially dechlorinated in the ortho position, but also doubly flanked and singly flanked meta- or para-chlorine substituents were removed. We used a newly designed computer-assisted direct cell counting protocol and quantitative PCR to demonstrate that strain CBDB1 uses chlorophenols as electron acceptors for respiratory growth. The growth yield of strain CBDB1 with 2,3-dichlorophenol was 7.6 × 1013 cells per mol of Cl- released, and the growth rate was 0.41 day-1. For strain 195, fast ortho dechlorination of 2,3-dichlorophenol, 2,3,4-trichlorophenol, and 2,3,6-trichlorophenol was detected, with only the ortho chlorine removed. Because chlorinated phenolic compounds are widely distributed as natural components in anaerobic environments, our results reveal one mode in which the Dehalococcoides species could have survived through earth history.Keywords
This publication has 23 references indexed in Scilit:
- Development and Characterization of Stable Sediment-Free Anaerobic Bacterial Enrichment Cultures That Dechlorinate Aroclor 1260Applied and Environmental Microbiology, 2006
- Complete Genome Sequence of the Dehalorespiring Bacterium Desulfitobacterium hafniense Y51 and Comparison with Dehalococcoides ethenogenes 195Journal of Bacteriology, 2006
- Genome Sequence of the PCE-Dechlorinating BacteriumDehalococcoides ethenogenesScience, 2005
- Genetic Identification of a Putative Vinyl Chloride Reductase in Dehalococcoides sp. Strain BAV1Applied and Environmental Microbiology, 2004
- Characterization of a Highly Enriched Dehalococcoides -Containing Culture That Grows on Vinyl Chloride and TrichloroetheneApplied and Environmental Microbiology, 2004
- Populations Implicated in Anaerobic Reductive Dechlorination of 1,2-Dichloropropane in Highly Enriched Bacterial CommunitiesApplied and Environmental Microbiology, 2004
- Delta-wing function of webbed feet gives hydrodynamic lift for swimming propulsion in birdsNature, 2003
- SULFUR TUFT AND TURKEY TAIL: Biosynthesis and Biodegradation of Organohalogens by BasidiomycetesAnnual Review of Microbiology, 1997
- An improved method of preparing wet mounts for photomicrographs of microorganismsJournal of Microbiological Methods, 1986
- Vertebrate Central Nervous System: Same Neurons Mediate Both Electrical and Chemical InhibitionsScience, 1976