Rare Actinobacteria, known as non-Streptomyces, hold great potential to produce new bioactive compounds for drug development. A strain designated DSW09T, which belongs those rare Actinobacteria, was isolated from surface seawater of the East China Sea. The cells were aerobic, Gram-positive, non-motile, non-spore-forming and rod-shaped (0.4 µm wide and 1.5-4.0 µm long). The closest relative was Euzebya tangerina F10T (96.46 % of 16S rRNA gene similarity). Cell growth occurred at 15-45 °C (optimum, 25-30 °C), at pH 6.0-9.0 (pH 6.0-7.0) and at NaCl concentrations of 0.5-5.0 % (w/v; 1.0-4.0 %). The major cellular fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C15 : 0iso 2OH), C17 : 1ω8c and C16 : 0. The predominant polar lipid was diphosphatidylglycerol. The predominant menaquinone was MK-9(H4). The cell-wall peptidoglycan was A1 γ-type, containing meso-DPA. The major cell-wall sugars were rhamnose and ribose. The genome size was 5 509 297 bp with a 71.29 mol% G+C content for strain DSW09T, while 4 781 440 bp with a 68.87 mol% G+C content for E. tangerina F10T. The average nucleotide identity and digital DNA-DNA hybridization values between strain DSW09T and E. tangerina F10T were 73.44 % and 16.43 %, respectively. Based on phylogenetic, phenotypic, chemotaxonomic evidence and genomic analyses, strain DSW09T is a novel species of genus Euzebya, for which the name Euzebya rosea sp. nov. is proposed. The type strain is DSW09T (=DMS 104446T=MCCC 1K03290T).
Keywords: Euzebya rosea; rare Actinobacteria; surface seawater; taxonomy; whole genome sequence.