Serinicoccus marinus gen. nov., sp. nov., a novel actinomycete with L-ornithine and L-serine in the peptidoglycan

A Gram-positive bacterial strain containing L-ornithine as the diagnostic diamino acid was isolated from a sea-water-sample from the East Sea, Korea. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain JC1078^T represents a phyletic line within the suborder Micrococcineae of the order Actinomycetales, adjacent to the genus Ornithinimicrobium. The highest sequence similarity values to the isolate were observed against Ornithinimicrobium humiphilum (94.3%) and Kytococcus sedentarius (94.1%). The strain was strictly aerobic and moderately halophilic with optimal growth at 2-3 % (w/v) NaCl. Cells were non-motile, non-sporulating and coccoid-shaped. The cell wall contains L-ornithine, glutamic acid, alanine, glycine and serine. The major menaquinone was MK-8(H₄). The predominant cellular fatty acids were of the iso- and anteiso-methyl-branched types. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and an unknown glycolipid. The acyl type of the glycan chain of peptidoglycan is acetyl. The DNA G+C content was 72 mol%. The combination of physiological, biochemical and chemotaxonomical data clearly separated the marine isolate from other members of the suborder Micrococcineae. On the basis of polyphasic evidence, it is proposed to classify strain JC1078^T in a novel genus and species, for which the name Serinicoccus marinus gen. nov., sp. nov. is proposed. The type strain is JC1078^T (=IMSNU 14026^T = KCTC, 9980^T = DSM 15273^T).