Roseicyclus marinus sp. nov., isolated from a Synechococcus culture, and emended description of the genus Roseicyclus.

A novel Gram-stain-negative, aerobic, non-flagellated, pink-pigmented and rod-shaped strain with gliding motility, designated strain CCMM001T, was isolated from a mixed culture of Synechococcus species PCC7002 and a natural bacterial community from a sample of offshore seawater from Qingdao, China, during September 2014. The strain contained bacteriochlorophyll a with a small peak at 802 nm and a large in vivo absorption band at 870 nm. Strain CCMM001T grew optimally at pH 7.0 and 30 °C in the presence of 3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CCMM001T is most closely related to the genus Roseicyclus and its type and only species Roseicyclus mahoneyensis ML6T with 96.9 % sequence similarity. The polar lipids of strain CCMM001T consisted of phosphatidylethanolamine, phosphatidylcholine, one unidentified aminolipid, and five unidentified lipids. The predominant isoprenoid quinone was Q-10. The major fatty acids included C18 : 1ω7c and C19 : 0cyclo ω8c. The DNA G+C content of strain CCMM001T was 63.5 mol%. These phylogenetic, physiological and chemotaxonomic data indicated that strain CCMM001T represents a novel species of the genus Roseicyclus, for which the name Roseicyclus marinus sp. nov. is proposed. The type strain is CCMM001T (=MCCC 1K03242T=KCTC 52641T).