Bacteria Genomes - DEHALOCOCCOIDES ETHENOGENES

Dehalococcoides ethenogenes is the only bacterium known to reductively dechlorinate the groundwater pollutants, tetrachloroethene (PCE) and trichloroethene, to ethene.

Tetrachloroethene (PCE) a human carcinogen, and trichloroethene (TCE) are among the most pervasive organic groundwater pollutants, primarily because of their disposal after use as industrial cleaners. Aerobic biodegradation of these solvents is ineffective, however, under anaerobic conditions, they can serve as terminal electron acceptors for dehalorespiration by bacteria that sequentially dechlorinate PCE to less chlorinated ethenes. Most cultured anaerobic (de)halorespirers (for example, S.multivorans and D. restrictus) only perform incomplete reductive dechlorination, yielding the toxic end product cis-dichloroethene (DCE). In contrast, Dehalococcoides ethenogenes performs complete reductive dechlorination of PCE and TCE to the nontoxic metabolite ethene

Its 1,469,720-base pair chromosome contains large dynamic duplicated regions and integrated elements.

Genome analysis provides insights into the organism's complex nutrient requirements and suggests that an ancestor was a nitrogen-fixing autotroph.

D. ethenogenes strain 195 was derived from an anaerobic sewage digestor.

References:

http://www.tigr.org/tigr-scripts/CMR2/GenomePage3.spl?database=gde
http://www.stormingmedia.us/84/8497/A849753.html