Marinobacterium aestuarii sp. nov., a benzene-degrading marine bacterium isolated from estuary sediment.

A Gram-stain-negative, aerobic, motile, flagellated rod-shaped bacterium, designated ST58-10, was isolated from an estuarine sediment in the Republic of Korea. The strain was able to degrade benzene. Growth of strain ST58-10 was observed at 4-35 °C (optimum, 20-25 °C), pH 5-9 (optimum, pH 7-8) and 1-8 % NaCl (optimum, 3 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain ST58-10 formed a phyletic lineage within the genus Marinobacterium of the family Oceanospirillaceae. Strain ST58-10 was most closely related to Marinobacterium profundum PAMC 27536 (99.6 %) and Marinobacterium rhizophilum CL-YJ9 (98.3 %), and to other members of the genus Marinobacterium(94.5-91.5 %). However, the mean value estimated by using the Genome-to-Genome Distance Calculator was 50.6±7.4 % with M. profundum PAMC 27536 and 30.9±2.8 with M. rhizophilum CL-YJ9, respectively. An average nucleotide identity value was 89.0 % with M. profundum PAMC 27536 and 85.6 % with M. rhizophilum CL-YJ9, respectively. The major fatty acids of strain ST58-10 were summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c), summed feature 8 (comprising C18 : 1 ω7c/C18 : 1ω6c), C16 : 0 and C10 : 0 3-OH, and contained ubiquinone (Q-8) as the sole isoprenoid quinone. Phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminolipids, an unidentified glycolipid and an unidentified lipid were detected as polar lipids. The DNA G+C content of strain ST58-10 was 58.78 mol%. On the basis of the phenotypic, chemotaxonomic and molecular properties, strain ST58-10 represents a novel species of the genus Marinobacterium, for which the name Marinobacterium aestuarii sp. nov. is proposed. The type strain is ST58-10 (=KCTC 52193=NBRC 112103).