Genome Sequence of the PCE-Dechlorinating Bacterium Dehalococcoides ethenogenes
Rekha Seshadri,1*
Lorenz Adrian,2
Derrick E. Fouts,1
Jonathan A. Eisen,1,3
Adam M. Phillippy,1
Barbara A. Methe,1
Naomi L. Ward,1,4
William C. Nelson,1
Robert T. Deboy,1
Hoda M. Khouri,1
James F. Kolonay,1
Robert J. Dodson,1
Sean C. Daugherty,1
Lauren M. Brinkac,1
Steven A. Sullivan,1
Ramana Madupu,1
Karen E. Nelson,1
Katherine H. Kang,1
Marjorie Impraim,1
Kevin Tran,1
Jeffrey M. Robinson,1
Heather A. Forberger,1
Claire M. Fraser,1,5
Stephen H. Zinder,6
John F. Heidelberg1,4
Dehalococcoides ethenogenes is the only bacterium known to reductively dechlorinate the groundwater pollutants, tetrachloroethene (PCE) and trichloroethene, to ethene. Its 1,469,720–base pair chromosome contains large dynamic duplicated regions and integrated elements. Genes encoding 17 putative reductive dehalogenases, nearly all of which were adjacent to genes for transcription regulators, and five hydrogenase complexes were identified. These findings, plus a limited repertoire of other metabolic modes, indicate that D. ethenogenes is highly evolved to utilize halogenated organic compounds and H2. Diversification of reductive dehalogenase functions appears to have been mediated by recent genetic exchange and amplification. Genome analysis provides insights into the organism's complex nutrient requirements and suggests that an ancestor was a nitrogen-fixing autotroph.
1 The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA.
2 Fachgebiet Technische Biochemie, Institut für Biotechnologie, Technische Universität Berlin, Seestrasse 13, D-13353 Berlin, Germany.
3 Johns Hopkins University, Charles and 34th Streets, Baltimore, MD 21218, USA.
4 Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, MD 21202, USA.
5 Departments of Pharmacology and Microbiology and Tropical Medicine, George Washington University School of Medicine, 2300 Eye Street N.W., Washington, DC 20037, USA.
6 Section of Microbiology, Cornell University, 272 Wing Hall, Ithaca, NY 14853-5701, USA.
* To whom correspondence should be addressed. E-mail: rekha{at}tigr.org
