Distribution of the Coenzyme M Pathway of Epoxide Metabolism Among Ethene- and Vinyl Chloride-Degrading Mycobacterium Strains

摘要

An epoxyalkane:coenzyme M (CoM) transferase (EaCoMT) enzyme was recently found to be active in the aerobic vinyl chloride (VC) and ethene assimilation pathways of Mycobacterium strain JS6O. In the present study, EaCoMT activity and genes were investigated in 10 different mycobacteria isolated on VC or ethene from diverse environmental samples. In all cases, epoxyethane metabolism in cell extracts was dependent on CoM, with average specific activities of EaCoMT between 380 and 2,910 nmol/min/ mg of protein, PCR with primers based on conserved regions of EaCoMT genes from Mycobacterium strain JS6O and the propene oxidizers Xanthobacter strain Py2 and Rhodococcus strain B- 276 yielded fragments (834 bp) of EaCoMT genes from all of the VC- and ethne- assimilating isolates. The Mycobacterium EaCoMT genes form a distinct cluster and are more closely related to the EaCoMT of Rhodococcus strain B%276 than that of Xanthobacter strain ....... The CoM-mediated pathway of epoxide metabolism appears to be universal in alkene-assimilating mycobacteria, possibly because of plasmid-mediated lateral gene transfer.