Pseudopontixanthobacter vadosimaris gen. nov., sp. nov., isolated from shallow sea near Kueishan Island.

A Gram-stain-negative and aerobic bacterial strain, designated as JL3514T, was isolated from surface water of the hydrothermal system around Kueishan Island. The isolate formed red colonies and cells were non-flagellated, rod-shaped and contained methanol-soluble pigments. Growth was observed at 10-50 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-9 % (w/v) NaCl (optimum, 2 %). Strain JL3514T was positive for catalase and weakly positive for oxidase. Results of 16S rRNA gene sequence analyses showed highest similarities to species in the family Erythrobacteraceae, namely Croceibacterium atlanticum (96.1 %), Pelagerythrobacter marensis (96.0 %), Tsuneonella rigui (96.0 %) and Altericroceibacterium xinjiangense (96.0 %). Phylogenetic analysis based on core gene sequences revealed that the isolate formed a distinct branch with the related species and it had a lower average amino acid identity value than the suggested threshold for genera boundaries. The major fatty acids (>5 %) were summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c), summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c), C16 : 0, C17 : 1  ω6c, C14 : 0 2-OH and C12 : 0. The dominant polar lipids comprised diphosphatidylglycerol, sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, glycolipid, two unidentified lipids and one unidentified phospholipid. The main respiratory quinones were ubiquinone-10 (95.7 %) and ubiquinone-9 (4.3 %). The DNA G+C content from the genome was 63.0 mol%. Based on the presented data, we consider strain JL3514T to represent a novel genus of the family Erythrobacteraceae, with the name Pseudopontixanthobacter vadosimaris gen. nov., sp. nov. The type strain is JL3514T (=KCTC 62623T=MCCC 1K03561T).