Caldovatus sediminis gen. nov., sp nov., a moderately thermophilic bacterium isolated from a hot spring

A Gram-stain-negative, ovoid-shaped, aerobic, non-motile, catalase-and oxidase-positive, and moderately thermophilic bacterial strain, designated strain YIM 72346(T), was isolated from a sediment sample collected from a hot spring in Tengchong county, Yunnan province, south-west China. Growth occurred at 37-50 degrees C (optimum, 45 degrees C), at pH 6.0-9.0 (optimum, pH 6.5-7.0) and in the presence of 0.5-1.0% (w/v) NaCl (optimum, 0.5 %). The major cellular fatty acids were C-18 : 1 omega 7c, C-16 : 0, C(19 : 0)cyclo omega 8c, and C-18 : 1 2-OH. The genomic DNA G+C content was determined to be 69.8 mol%. The predominant ubiquinone was Q-10. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and two unidentified phospholipids. Bacteriochlorophyll alpha and carotenoic acids were not detected. Strain YIM 72346(T) was not observed for the accumulation of poly-beta-hydroxybutyrate. The strain shared highest 16S rRNA gene sequence identities with Crenalkalicoccus roseus YIM 78023(T) (93.3 %) and Craurococcus roseus NS130(T) (92.7 %), but formed a distinct lineage within the family Acetobacteraceae in the phylogenetic trees. On the basis of genotypic, phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM 72346(T) is considered to represent a novel genus and species of the family Acetobacteraceae, for which the name Caldovatus sediminis gen. nov., sp. nov. is proposed. The type strain of Caldovatus sediminis is YIM 72346(T) (=KCTC 52714(T)=CGMCC 1.16330(T)).