Shumkonia mesophila gen. nov., sp. nov., a novel representative of the order Rhodospirillales and proposal of Shumkoniaceae fam. nov

Abstract

Abstract A facultatively anaerobic, mesophilic, chemoorganoheterotrophic bacterium, designated YP2T, was isolated from oil sludge enrichment in China. Cells of the strain were Gram-stain-negative, non-motile, rod-shaped or slightly curved with 0.8–3.0 µm in length and 0.4–0.6 µm in diameter. Spore formation was not observed. The strain YP2T grew optimally at 25 oC (range from 15 to 30 oC) and pH 7.1 (range from pH 7.1 to 8.3) without NaCl. The major cellular fatty acids were C16:0, sum in feature 3 (C16:1 ω7c and/or C16:1 ω6c), sum in feature 8 (C18:1 ω7c and/or C18:1 ω6c), and the main polar lipids were aminolipid, phosphatidylethanolamine, phosphatidylglycerol, phospholipid and unidentified lipids. The respiratory quinone was Q-10. The DNA G + C content was 66.0%. Strain YP2T shared 90.2% 16S rRNA gene sequence similarity with the most related Oceanibaculum nanhaiense L54-1-50T belonging to the order Rhodospirillales of the class Alphaproteobacteria. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain YP2T formed a distinct evolutionary lineage within the order Rhodospirillales. On the basis of phenotypic, phylogenetic and phylogenomic data, we propose that strain YP2T represents a novel species in a novel genus, for which Shumkonia mesophila gen. nov., sp. nov., within a new family Shumkoniaceae fam. nov.. The type strain is YP2T (= CCAM 826T = JCM 34766T).