Characterization of Jannaschia halovivens sp. nov., Isolated from Seawater.

Phenotypic, physiological, phylogenetic, genomic, and chemotaxonomic analyses were carried out on a bacterium, designated as KMU-145T, isolated from seawater gathered in the Republic of Korea. Strain KMU-145T was ovoid-shaped, Gram-reaction-negative, non-motile, obligately aerobic, and formed apricot-colored colonies on marine agar 2216. The strain grew at 15-37 °C, pH 6.0-9.5, and 0-2.0% NaCl concentrations (w/v). Preliminary evaluation based on 16S rRNA gene sequence showed that strain KMU-145T was affiliated with the genus Jannaschia, family Roseobacteraceae, showing the greatest sequence similarity (98.4%) to "J. ovalis" GRR-S6-38T. The only respiratory quinone was ubiquinone-10, and the main (> 10%) fatty acids were C18:1 ω7c, C18:1 ω7c 11-methyl, and C18:0. Phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, three unidentified aminolipids, and three unidentified lipids were found as polar lipids. Strain KMU-145T had a 3.5 Mbp genome with a 68.5% G+C content. The pairwise ANI values between the genomes of strain KMU-145T and other species of the genus Jannaschia were 70.9-79.3%. Strain KMU-145T exhibited 21.6% dDDH value with strain "J. ovalis" GRR-S6-38T. The genome of strain KMU-145T contained numerous carbohydrate-active enzymes, suggesting a significant potential for the development of enzymes with practical applications in industry. Therefore, the marine strain represents a novel member of the genus Jannaschia, for which the name Jannaschia halovivens sp. nov., is proposed with the type strain KMU-145T (= KCCM 90597T = NBRC 117092T).