Marinicaulis aureum sp. nov., isolated from a culture of the green alga Ulva prolifera, and emended description of the genus Marinicaulis.

A Gram-stain negative, facultatively anaerobic, rod-shaped motile bacterium with a single polar flagellum, designed strain HHTR114T, was isolated from a culture of the green alga Ulva prolifera obtained from offshore seawater at Qingdao, China. Optimum growth occurred in the presence of 2-3% (w/v) NaCl, at pH 7.0-8.0 and 30 °C. The major fatty acids (> 10% of total fatty acids) were C16:0 (24.7%), C18:1ω7c 11-methyl (24.3%) and summed feature 3 (C16:1ω6c and/or C16:1ω7c, 19.7%). The major polar lipids were phosphatidylethanolamine, glycolipid and four unidentified polar lipids. The DNA G + C content of strain HHTR114T calculated on the basis of the genome sequence was 58.2% and the genome size is 4.1 Mbp. The predominant isoprenoid quinone was Q-10. The estimated DNA-DNA hybridization values were 21.4% [18.6-24.4%] between strain HHTR114T and Marinicaulis flavus SY-3-19T. On the basis of polyphasic analysis, strain HHTR114T is considered to represent a novel species, for which the name Marinicaulis aureum sp. nov. is proposed. The type strain of the type species is HHTR114T (= KCTC 62394T = MCCC 1K03481T).