A moderately halophilic actinomycete, designated HA-9 T , was isolated from a saltern in Kunsan, Republic of Korea, and was the subject of polyphasic identification. Analysis of 16S rDNA indicated that the isolate belonged to the genus Nocardiopsis, but differed genetically from other Nocardiopsis species. Strain HA-9T contained meso-diaminopimelic acid, no diagnostic sugars, hexaor octa-hydrogenated menaquinones with 10 isoprene units, straight-chain saturated or monounsaturated, iso-, anteiso-, 10-methyl branched fatty acids with 13-18 carbons and type III phospholipids. All of these characters consistently assign the isolate to the genus Nocardiopsis. All of the validly described Nocardiopsis species, including moderately halophilic Nocardiopsis halophila, can be differentiated from the saltern isolate using morphological and physiological traits. On the basis of polyphasic evidence, the name Nocardiopsis kunsanensis sp. nov. is proposed for strain HA-9 T (l KCTC 9831 T ), which is designated the type strain.Keywords : Nocardiopsis kunsanensis sp. nov., polyphasic taxonomy, 16S rDNA sequencing
INTRODUCTIONThe genus Nocardiopsis was created by Meyer (1976) to harbour Actinomadura dassonvillei on the basis of morphological and chemotaxonomic properties. The genus currently comprises seven validly described species, namely Nocardiopsis alba, Nocardiopsis dassonvillei, Nocardiopsis halophila, Nocardiopsis listeri, Nocardiopsis lucentensis, Nocardiopsis prasina and Nocardiopsis synnemataformans Kroppenstedt, 1992 ;Yassin et al., 1993Yassin et al., , 1997. The members of Nocardiopsis are phylogenetically coherent and form a monophyletic clade that is equated with the family Nocardiopsaceae (Rainey et al., 1996). None of the Nocardiopsis species to date have been reported as halophilic except N. halophila, which can grow best at 5-15 % NaCl . In this study, we report the results of polyphasic identification of an actinomycete strain, designated HA-9 T , isolated from a saltern sample. optimally in medium containing 10 % NaCl and showed properties consistent with its classification in the genus Nocardiopsis Meyer 1976 as a new species, of which the name Nocardiopsis kunsanensis sp. nov. is proposed.
METHODSBacterial strains. The saltern sample was collected from Kunsan, Republic of Korea. Bacterial strains were isolated by plating serially diluted samples onto Bennett medium based on seawater (2 g glucose, 1 g yeast extract, 1 g malt extract, 2 g peptone, 20 g agar, 1 l aged seawater, pH 7n2). After incubating at 30 mC for 2 weeks, a visible colony, designated HA-9 T , was transferred and subcultured until pure culture was obtained. Complex medium (CM ; 7n5 g Casamino acids, 10 g yeast extract, 3 g sodium citrate, 10 g magnesium sulfate, 2 g potassium chloride, 1 ml 4n98 % iron sulfate, 100 g NaCl, 1 l distilled water, pH 7n4) was used for growing strain HA-9 T and Nocardiopsis halophila KCTC 9825 T (l A.S.4.1195). The strain was maintained as a glycerol suspension (20 %, w\v) at k80 mC. J. Chun and others colonies, ...