Biochemistry, Genomics, and Ecophysiology of Reductive Dehalogenation
Chloroethenes, such as tetrachloroethene (PCE) and trichlorethene (TCE) are the most prevalent groundwater contaminants in the developed world, and clean-up costs are estimated to be billions of dollars. Bioremediation of these chlorinated ethenes to harmless ethene is a stepwise, strictly anaerobic process where each chlorine atom is sequentially eliminated reductively as Cl-. Most important are microbial catabolic reductive dehalogenation using H2 as electron donor. Complete reductive dehalogenation of PCE or TCE is mediated by two physiologically distinguishable groups of microorganisms. Group one consists of phylogenetically diverse anaerobes, such as, Desulfitobacterium species but also Dehalococcoides sp, and typically mediate dehalogenation to cDCE. The second group consists so far only of Dehalococcoides (Dhc) species, which are phylogenetically deeply branching Chloroflexi, that mediate reduction of c-DCE and vinyl chloride to ethene.
- Enzymology and maturation of reductive dehalogenases
- Diversity of reductive dehalogenases in natural, non-contaminated environments
- Evolution of reductive dehalogenases and dehalogenating microorganisms