Caenispirillum bisanense gen. nov., sp. nov., isolated from sludge of a dye works

Two Gram-negative, non-spore-forming, motile and helical-shaped bacterial strains, K92^T and K93, were isolated from sludge from a dye works in Korea, and their taxonomic positions were investigated by means of a polyphasic approach. Strains K92^T and K93 grew optimally at 37°C and pH 7.0-8.0 in the presence of 0.5% (w/v) NaCl. They contained Q-10 as the predominant ubiquinone and C_18:1 ω7c as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and two unidentified amino-group-containing lipids that were ninhydrin-positive. Their DNA G+C contents were 70.0 mol%. The 16S rRNA gene sequences of K92^T and K93 showed no differences, and the two strains had a mean DNA-DNA relatedness of 93%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains K92^T and K93 formed a distinct evolutionary lineage within the Alphaproteobacteria. The 16S rRNA gene sequences of strains K92^T and K93 exhibited similarity values of less than 91.5% with respect to the 16S rRNA gene sequences of other members of the Alphaproteobacteria. The two strains were distinguishable from phylogenetically related genera through differences in several phenotypic properties. On the basis of the phenotypic, phylogenetic and genetic data, strains K92^T and K93 represent a novel genus and species, for which the name Caenispirillum bisanense gen. nov., sp. nov. is proposed. The type strain of Caenispirillum bisanense is K92^T (=KCTC 12839^T = JCM 14346^T).