Pseudophaeobacter flagellatus sp. nov., isolated from coastal water

Abstract

A Gram-stain-negative, aerobic, motile, rod-shaped novel bacterial strain, designated as MA21411-1T, was isolated from the Korean coast. The colonies were white-yellow-coloured, smooth, convex and entire, spherical and 1.0-1.8 mm in diameter. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain MA21411-1T is closely related to species of the genus Pseudophaeobacter. The 16S rRNA gene sequence similarities between strain MA21411-1T and Pseudophaeobacter arcticus DSM 23566T, Phaeobacter porticola DSM 103148T and Pseudophaeobacter leonis DSM 25627T were 98.31, 97.80 and 97.28 %, respectively. Strain MA21411-1T has a draft genome size of 4 294 042 bp, annotated with 4125 protein-coding genes, and 53 tRNA, three rRNA and one tmRNA genes. The genomic DNA G+C content was 59.2 mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain MA21411-1T and other related species were below the cut-off levels of 95, 70 and 95.5 %, respectively. The growth temperature range for growth was 15-28 °C (optimum, 25 °C), pH range was 6.0-9.0 (optimum, pH 6.0), and salt tolerance range was 0.5-4 % (optimum 0.5 %). Ubiquinone-10 was the sole quinone present in MA21411-1T and all three closely related strains. The major cellular fatty acid (>10 %) of the strain was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and four unidentified polar lipids. Based on the phylogenetic tree, as well as phenotypic, chemotaxonomic and genomic features, strain MA21411-1T represents a novel species of the genus Pseudophaeobacter, for which the name Pseudophaeobacter flagellatus sp. nov. is proposed. The type strain is MA21411-1T (=KCTC 92095T=GDMCC 1.2988T).