Marinicaulis flavus gen. nov., sp. nov., a novel stalked bacterium of the family Parvularculaceae

A Gram-stain-negative, aerobic, ovoid or short rod-shaped bacterium with prosthecates and flagella, designated SY-3-19 T , was isolated from the surface seawater of the South China Sea, and subjected to a polyphasic taxonomic study. The isolate grew at 4-40 °C and pH 5.0-9.0 (optimum 28 °C and pH 6.5-7.5), and with 0.5-16.0 % (w/v) NaCl (optimum 4 %). It was positive for oxidase and catalase activity. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SY-3-19 T constituted a separate branch in the family Parvularculaceae, sharing the highest sequence similarities to the genera Aquisalinus (91.9 %), Amphiplicatus (91.1 %) and Parvularcula(91.0-89.4 %). The sole respiratory quinone was ubiquinone-10 and the principal fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), 11 methyl C18 : 1ω7c and C16 : 0. The polar lipids of strain SY-3-19 T consisted of phosphatidylglycerol, nine unidentified glycolipids and four unidentified lipids. The DNA G+C content was 60.9 mol%. On the basis of morphological, physiological and chemotaxonomic characteristics, together with the results of phylogenetic analysis, strain SY-3-19 T is described as a novel species in a novel genus, for which the name Marinicaulis flavus gen. nov., sp. nov. (type strain SY-3-19 T =MCCC 1K03432 T =KCTC 62156 T ) is proposed.