Nocardioides rotundus sp. nov., isolated from deep seawater.

A Gram-staining-positive, aerobic, coccoid-shaped, non-motile actinobacterium, designated strain GY0594T, was isolated from deep seawater of the western Pacific. Phylogenetic analyses based on 16S rRNA gene sequences showed that this strain was affiliated with the genus Nocardioides with low 16S rRNA gene sequence similarities ( ≤ 96.0 %) with members of the genus Nocardioides. Chemotaxonomic characterization of strain GYP0594T supported the result of the phylogenetic analysis. The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The major menaquinone was MK-8(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unidentified lipid and six unidentified phospholipids. The major cellular fatty acids were iso-C16 : 0 and C18 : 1ω9c. The DNA G+C content of strain GY0594T was determined to be 71.2 mol%. However, strain GY0594T could be distinguished from closely related species by cell morphology, nitrate reduction, aesculin hydrolysis, activity of urease, cystine arylamidase, trypsin and acid phosphatase, assimilation of N-acetylglucosamine, maltose, adipic acid, malic acid and phenylacetate, and significant differences in the proportions of several fatty acids. In conclusion, based on the data presented, strain GY0594T should be placed in the genus Nocardioides as a representative of a novel species, for which the name Nocardioides rotundus sp. nov. is proposed. The type strain is GY0594T ( = MCCC 1A10561T = KCTC 39638T).