Salinimonas iocasae sp. Nov., a halophilic bacterium isolated from a polychaete tube in a hydrothermal field

A moderately halophilic bacterium, designated strain KX18D6^T, was isolated from the tube of the polychaete Paralvinella hessleri collected from a hydrothermal field located in the Okinawa Trough. Strain KX18D6^T was Gram-stain-negative, rod-shaped, facultatively anaerobic, motile, oxidase-and catalase-positive, and grew optimally at 30–35 °C, pH 7.0 and in the presence of 3–5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KX18D6^T grouped with the members of the genus Salinimonas, including Salinimonas chungwhensis BH030046T (97.7% sequence similarity), Salinimonas lutimaris DPSR-4^T (97.2%) and Salinimonas sediminis N102^T (96.4%). Genome sequencing of strain KX18D6^T revealed a genome size of 4.16 Mb and a DNA G+C content of 47.3 mol%. Genomic average nucleotide identity (orthoANI) values of strain KX18D6^T with S. chungwhensis DSM 16280^T, S. lutimaris KCTC 23464^T and S. sediminis N102^T were 76.2, 73.1 and 73.2%, respectively, while the in silico DNA–DNA hybridization (GGDC) values for strain KX18D6^T with these strains were 25.3, 17.7 and 18.0%, respectively. The major fatty acids were summed feature 3 (C_16:1 ω7c/C_16:1 ω6c), C_16:0 and summed feature 8 (C_18:1 ω7c/C_{18: 1} ω6c). The predominant respiratory quinone was ubiquinone 8, and the predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol. On the basis of comparative analysis of phylogenetic, phylogenomic, phenotypic and chemotaxonomic characteristics, strain KX18D6^T (=KCTC 72464^T=MCCC 1K03884^T) is clearly distinguishable from the type strains of species of the genus Salinimonas and is considered to represent a novel species of the genus Salinimonas, for which the name Salinimonas iocasae sp. nov. is proposed.