Chlorinated aliphatic hydrocarbon-induced degradation of trichloroethylene in Wautersia numadzuensis sp. nov.

Two strains of trichloroethylene (TCE)-degrading bacteria were isolated from soils at polluted and unpolluted sites. The isolates, strains TE26(T) and K6, showed co-substrate-independent TCE-degrading activity. TCE degradation was accelerated by preincubation with tetrachloroethylene, cis-dichloroethylene (DCE) and 1,1-DCE. TCE-degrading activities of strains TE26(T) and K6 were 0.23, 0.24 micromol min(-1) g(-1) dry cells, respectively. 16S rDNA sequences of strains TE26(T) and K6 were almost identical (99.7% similarity), and most closely related to Ralstonia basilensis (ATCC17697(T)) (98.5% similarity). From the results of DNA-DNA hybridizations, strain TE26(T) was genetically coherent to strain K6 (94 and 88% hybridization), and exhibited lower relatedness to R. basilensis (DSM11853(T)) (44% and 15%). In addition, because of the differences in chemotaxonomic properties, strain TE26(T) and strain K6 appear to be distinct from all established species of the Ralstonia group. Based on these results and the proposal of transferring R. basilensis and related species to Wautersia gen. nov., we propose that these strains should be assigned to the genus Wautersia as Wautersia numadzuensis sp. nov.