|
KMID : 1171820080230020001
|
|
Journal of Environmental and Sanitary Engineering
2008 Volume.23 No. 2 p.1 ~ p.18
|
|
|
Biochemical and molecular characterization of a tetrachloroethylene (PCE) dechlorinating Clostridium bifermentans DPH-1
|
|
Chang Young-Cheol
Tadashi Toyama
Shintaro Kikuchi
|
|
|
Abstract
|
|
|
|
The tetrachloroethylene (PCE) dehalogenase of Clostridium bifermentans DPH-1 (a halorespiring organism) was purified, cloned, and sequenced. This enzyme is a homodimer with a molecular mass of ca. 70 kDa and exhibits dehalogenation of dichloroethylene isomers along with PCE and trichloroethylene (TCE). Broad range of substrate specificity for chlorinated aliphatic compounds (PCE, TCE, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, 1,1-dichloroethylene. 1,2-dichloropropene, and 1,1,2-trichloroethane) for this enzyme was also observed. A mixture of propyl iodide and titanium citrate caused a light-reversible inhibition of enzymatic activity suggesting the involvement of a corrinoid cofactor. A partial sequence (81 bp) of the encoding gene for PCE dehalogenase was amplified and sequenced with degenerateprimers designed from the N-terrninal sequence (27 amino acid residues). Southern analysis of C. biiermentsns genomic DNA using the polymerase chain reaction product as a probe revealed restriction fragment bands. A 5.0 kb ClaI fragment, harboring the relevant gene (designated pceC) was cloned (pDEHAL5) and the complete nucleotide sequence of pceC was determined. The gene showed homology mainly with microbial membrane proteins and no homology with any known dehalogenase, suggesting a distinct PCE dehalogenase. So, C. bitermentsns could play some important role in the initial breakdown of PCE and other chlorinated aliphatic compounds in sites contaminated with mixtures of halogenated substances.
|
|
|
KEYWORD
|
|
|
tetrachloroethylene, Clostridium bifermentans DPH-1, PCE dehalogenase, pceC, gene cloning
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|