Marinobacter nanhaiticus sp. nov., polycyclic aromatic hydrocarbon-degrading bacterium isolated from the sediment of the South China Sea

A Gram-negative, rod-shaped, slightly halophilic and facultatively anaerobic bacterium, designated strain D15-8W^T, was isolated from the sediment of the South China Sea. Growth was found to occur optimally at 25 °C, between pH 7.0 and 8.0 and with 1–5 % (w/v) NaCl. The strain was observed to utilize a variety of organic substrates and polycyclic aromatic hydrocarbons as sole carbon sources. The G+C content of the genomic DNA was determined to be 58.7 %. The predominant respiratory quinone was found to be Q-9. The significant fatty acids were determined to be C_16:0, C_16:1 ω9c, C_18:1 ω9c, C_12:0 and C_14:0 3OH. Analysis of 16S rRNA gene sequences showed that strain D15-8W^T fits within the phylogenetic cluster of the genus Marinobacter and is most closely related to Marinobacter segnicrescens CGMCC 1.6489^T, Marinobacter bryozoorum DSM 15401^T, Marinobacter lacisalsi CECT 7297^T and Marinobacter daqiaonensis CGMCC1.9167^T. The DNA–DNA hybridization values between strain D15-8W^T and the type strains of the most closely related species were 42.3 % (CGMCC 1.6489^T), 39.8 % (DSM 15401^T), 37.3 % (CECT 7297^T) and 35.2 % (CGMCC1.9167^T). The results of this polyphasic study indicate that strain D15-8W^T represents a novel species of the genus Marinobacter, for which the name Marinobacter nanhaiticus sp. nov. is proposed. The type strain is D15-8W^T (=CGMCC 1.11019^T=KCTC 23749^T).