Dehalococcoides mccartyi strain JNA dechlorinates multiple chlorinated phenols including pentachlorophenol and harbors at least 19 reductive dehalogenase homologous genes.
Pentachlorophenol and other chlorinated phenols are highly toxic ubiquitous environmental pollutants. Using gas chromatographic analysis we determined that Dehalococcoides mccartyi strain JNA in pure culture dechlorinated pentachlorophenol to 3,5-dichlorophenol (DCP) via removal of the ortho and para chlorines in all of the three possible pathways. In addition, JNA dechlorinated 2,3,4,6-tetrachlorophenol via 2,4,6-trichlorophenol (TCP) and 2,4,5-TCP to 2,4-DCP and 3,4-DCP, respectively, and dechlorinated 2,3,6-TCP to 3-chlorophenol (CP) via 2,5-DCP. JNA converted 2,3,4-TCP to 3,4-DCP and 2,4-DCP by ortho and meta dechlorination, respectively. 2,3-DCP was dechlorinated to 3-CP, and, because cultures using it could be transferred with a low inoculum (0.5 to 1.5% vol/vol), it may act as an electron acceptor to support growth. Using PCR amplification with targeted and degenerate primers followed by cloning and sequencing, we determined that JNA harbors at least 19 reductive dehalogenase homologous (rdh) genes including orthologs of pcbA4 and pcbA5, pceA, and mbrA, but not tceA or vcrA. Many of these genes are shared with D. mccartyi strains CBDB1, DCMB5, GT, and CG5. Strain JNA has previously been shown to extensively dechlorinate the commercial polychlorinated biphenyl (PCB) mixture Aroclor 1260. Collectively the data suggest that strain JNA may be well adapted to survive in sites contaminated with chlorinated aromatics and may be useful for in situ bioremediation.
Department of Biological Sciences and ‡Department of Civil and Environmental Engineering, Rensselaer Polytechnic Institute , 110 8th Street, Troy, New York 12180, United States.
Ashwana D
AD
Fricker
Sarah L
SL
LaRoe
Michael E
ME
Shea
Donna L
DL
Bedard
D001419:Bacteria / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000737:chemistry / Q000378:metabolism*; D017931:DNA Primers / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015394:Molecular Structure; D016133:Polymerase Chain Reaction / Q000379:methods
D002733:Chlorophenols; D017931:DNA Primers; D004785:Environmental Pollutants