Phenylobacterium koreense sp. nov., isolated from South Korea.

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterium, Slu-01(T), was isolated from activated sludge from a wastewater treatment plant in Daejeon, South Korea. After 3 days on R2A medium, strain Slu-01(T) developed colourless colonies (0.7-1.2 mm). The non-motile rods (0.7-1.0 x 1.0-2.0 microm) were slightly curved and occurred singly and in pairs. No filamentous cells were found. On the basis of 16S rRNA gene sequence similarity, strain Slu-01(T) was shown to belong to the family Caulobacteraceae and was most closely related to Phenylobacterium immobile (96.6%) and Phenylobacterium lituiforme (96.5%). The genomic DNA G+C content of strain Slu-01(T) was 68.1 mol%, within the range of 67.3-68.4 mol% for the genus Phenylobacterium. Chemotaxonomic data (major ubiquinone, Q-10; major fatty acids C(18:1)omega7c, C(16:0), C(15:0) and C(17:0)) and 16S rRNA gene sequence analysis supported the affiliation of strain Slu-01(T) to the genus Phenylobacterium. However, DNA-DNA hybridization data and phenotypic properties showed that strain Slu-01(T) could be distinguished from the two other Phenylobacterium species with validly published names. Thus, it is suggested that strain Slu-01(T) represents a novel species of the genus Phenylobacterium, for which the name Phenylobacterium koreense is proposed. The type strain is Slu-01(T) (=KCTC 12206(T)=IAM 15119(T)).