Abstract
Thirty-one heavy-metal-resistant bacteria isolated from industrial biotopes were subjected to polyphasic characterization, including 16S rDNA sequence analysis, DNA--DNA hybridizations, biochemical tests, whole-cell protein and fatty-acid analyses. All strains were shown to belong to the Ralstonia branch of the beta-Proteobacteria. Whole-cell protein profiles and DNA--DNA hybridizations revealed two clearly distinct groups, showing low similarity to known Ralstonia species. These two groups, of 8 and 17 isolates, were assigned to two new species, for which the names Ralstonia campinensis sp. nov. and Ralstonia metallidurans sp. nov. are proposed. The type strains are WS2(T) (=LMG 19282(T)=CCUG 44526(T)) and CH34(T) (=LMG 1195(T)=DSM 2839(T)), respectively. Six isolates were allocated to Ralstonia basilensis, which presently contains only the type strain; an emendation of the latter species description is therefore proposed.