Solimonas fluminis sp. nov., isolated from a freshwater river

A strictly aerobic, catalase-negative and oxidase-positive bacterium (HR-BB^T), isolated from a water sample of the Han River, was taxonomically studied using a polyphasic approach. Cells were Gram-stain-negative motile rods with a polar flagellum. The strain grew at 20-35 °C and pH 7-8 and in the absence of NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-BB^T belonged to the family Nevskiaceae in the phylum Proteobacteria and formed a phylogenic lineage with members of the genus Solimonas. A comparison of the 16S rRNA gene sequences of strain HR-BB^T and the type strains of closely related species of the genus Solimonas showed that it shared highest sequence similarity with Solimonas terrae KIS83-12^T (94.9 %), Solimonas soli DCY12^T (94.8 %), Solimonas variicoloris MN28^T (94.4 %) and Solimonas flava CW-KD 4^T (94.2 %). The fatty acids of the strain consisted of summed features 8 (comprising C18 : 1ω6c and/or C18 : 1ω7c) and 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and C12 : 0 as major components. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified phospholipids and an unidentified lipid. Ubiquinone-8 was detected as the sole respiratory quinone. The DNA G+C content of strain HR-BB^T was 68.5 mol%. Based on the genotypic, chemotaxonomic and phenotypic analyses, strain HR-BB^T represents a novel species of the genus Solimonas, for which the name Solimonas fluminis sp. nov. is proposed. The type strain is HR-BB^T (=KACC 19410^T=JCM 32268^T).