Desulfovibrio idahonensis sp. nov., sulfatereducing bacteria isolated from a metal(loid)-contaminated freshwater sediment

Two novel sulfate-reducing bacteria, strains CY1^T and CY2, were isolated from heavy-metal-contaminated sediments of Lake Coeur d'Alene, Idaho, USA. Strains CY1^T and CY2 were found to contain c-type cytochromes and to reduce sulfate, sulfite, thiosulfate, elemental sulfur, DMSO, anthraquinone disulfonate and fumarate using lactate as an electron donor. In a comparison of 16S rRNA gene sequences, CY1^T and CY2 were found to be 100% identical, but only 97 and 92.4% similar, respectively, to the type strains of Desulfovibrio mexicanus and Desulfovibrio aminophilus. Unlike these species, however, CY1^T was neither able to disproportionate thiosulfate nor able to use yeast extract or amino acids as electron donors. These data, considered in conjunction with differences among strain CY1^T and the two related type strains in chemotaxonomy, riboprint patterns, temperature and pH optima, support recognition of a distinct and novel species within the genus Desulfovibrio, Desulfovibrio idahonensis sp. nov., with the type strain CY1^T (=DSM 15450^T =JCM 14124^T).