Marinobacter zhanjiangensis sp. nov., a marine bacterium isolated from sea water of a tidal flat of the South China Sea.

A novel Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped, aerobic bacterium, designated strain JSM 078120(T), was isolated from sea water collected from a tidal flat of Naozhou Island, South China Sea. Growth occurred with 1-15% (w/v) total salts (optimum, 2-4%), at pH 6.0-10.0 (optimum, pH 7.5) and at 4-35 degrees C (optimum, 25-30 degrees C). The major cellular fatty acids were C(18:1) omega9c, C(16:0), C(12:0) 3-OH and C(16:1) omega7c. The predominant respiratory quinone was ubiquinone Q-9, and the genomic DNA G + C content was 60.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 078120(T) should be assigned to the genus Marinobacter, being related most closely to the type strains of Marinobacter segnicrescens (sequence similarity 98.2%), Marinobacter bryozoorum (97.9%) and Marinobacter gudaonensis (97.6%). The sequence similarities between the novel isolate and the type strains of other recognized Marinobacter species ranged from 96.7 (with Marinobacter salsuginis) to 93.3% (with Marinobacter litoralis). The levels of DNA-DNA relatedness between strain JSM 078120(T) and the type strains of M. segnicrescens, M. bryozoorum and M. gudaonensis were 25.3, 20.6 and 18.8%, respectively. The combination of phylogenetic analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain JSM 078120(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter zhanjiangensis sp. nov. is proposed. The type strain is JSM 078120(T) (= CCTCC AB 208029(T) = DSM 21077(T) = KCTC 22280(T)).