Fretibacter rubidus gen. nov., sp. nov., isolated from seawater

A brick-red-coloured, curved-rod-shaped, prostheca-bearing and non-motile bacterial strain, designated JC2236^T, was isolated from a seawater sample of Jeju Island, Republic of Korea. 16S rRNA gene sequence analysis indicated that this strain belongs to the family Hyphomonadaceae and represents a distinct phyletic line that reflects a novel genus status within a clade containing the genera Litorimonas, Hellea, Robiginitomaculum and Algimonas. The predominant isoprenoid quinone (Q10) and polar lipid profile (phosphatidylglycerol, glucuronopyranosyl diglyceride and monoglycosyl diglyderide) were in line with those of most members of the family. However, the DNA G+C content (49.3 mol%), the abundance of C_16 : 0, the requirement of sea salts for growth and absence of cell motility differentiated strain JC2236^T from other closely related genera. Overall enzyme traits also demonstrated that the novel strain is not closely affiliated with any of the previously described genera. Thus, based on data from the present polyphasic taxonomic study, strain JC2236^T is considered to represent a novel species of a new genus belonging to the family Hyphomonadaceae, for which the name Fretibacter rubidus gen. nov., sp. nov. is proposed. The type strain of Fretibacter rubidus is JC2236^T ( = KACC 16935^T = JCM 15585^T).