Confluentimicrobium naphthalenivorans sp nov., a naphthalene-degrading bacterium isolated from sea-tidal-flat sediment, and emended description of the genus Confluentimicrobium Park et al. 2015

A Gram-staining-negative, aerobic and moderately halophilic bacterium, designated strain NS6(T), was isolated from sea-tidal-flat sediment of the South Sea in Korea. Cells were motile rods with a single flagellum showing positive catalase and oxidase activities. Strain NS6(T) grew at 15-40 degrees C (optimum, 30 degrees C), at pH 6.0-9.0 (optimum, pH 7.0-7.5) and in the presence of 1-5 % (w/v) NaCl (optimum, 2 %). Ubiquinone-10 was identified as the only isoprenoid quinone and summed feature 8 (comprising C-18 : 1 omega 7c/omega 6c), C-19 : 0 cyclo omega 8c, C-16 : 0 and C-10 : 0 3-OH were the major fatty acids. Strain NS6(T) contained phosphatidylglycerol, sulfoquinovosyldiacylglycerol, an unidentified amino lipid and an unidentified lipid as the major polar lipids. An unidentified phospholipid and three unidentified lipids were also detected as the minor polar lipids. The G+C content of the genomic DNA was 64.5 mol%. Strain NS6(T) was most closely related to Confluentimicrobium lipolyticum SSK1-4(T) with a 96.8 % 16S rRNA gene sequence similarity, and the phylogenetic analysis based on 16S rRNA gene sequences showed that strain NS6(T) formed a tight phylogenetic lineage with C. lipolyticum SSK1-4(T). The physiological, chemotaxonomic and phylogenetic properties suggest that strain NS6(T) represents a novel species of the genus Confluentimicrobium, for which the name Confluentimicrobium naphthalenivorans sp. nov. is proposed. The type strain is NS6(T) (=KCTC 18418(T) =JCM 30828(T)). An emended description of the genus Confluentimicrobium is also proposed.