Marinobacter panjinensis sp. nov., a moderately halophilic bacterium isolated from sea tidal flat environment

Two moderately halotolerant bacterium strains, designated PJ-16^T and PJ-38, were isolated from a tidal flat of the red beach in Panjin City, Liaoning Province, PR China. Cells were found to be Gram-stain-negative, aerobic, motile, rod-shaped with a single polar flagellum. Optimum growth of strain PJ-16^T occurred at 30 °C, pH 7.0 and 0.2-8.0  % (w/v) NaCl, and strain PJ-38 at 30 °C, pH 6.0-7.0 and 0.2-8.0  % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PJ-16^T was most closely related to Marinobacter denitrificans KCTC 62941^T (99.2 % 16S rRNA gene sequence similarity), Marinobacter algicola DSM 16394^T (98.6 %), Marinobacter salarius JCM 19399^T (98.4 %) and Marinobacter confluentis KCTC 42705^T (98.2 %), and strain PJ-38 was most closely related to M. denitrificans KCTC 62941^T (99.1 %), M. algicola DSM 16394^T (98.6 %), M. salarius JCM 19399^T (98.4 %) and M. confluentis KCTC 42705^T (98.1 %). The G+C content of the genomic DNA of strain PJ-16^T based on its draft genomic sequence was 57.4 mol%. The major cellular fatty acids of strain PJ-16^T were C_16 : 0, C_16 : 1  ω7c/C_16 : 1  ω6c and C_18 : 1  ω9c. The major respiratory quinone of PJ-16^T was ubiquinone-9 and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The results of the phenotypic, phylogenetic and genomic analyses revealed that strains PJ-16^T and PJ-38 represent a novel species of the genus Marinobacter, and the name Marinobacter panjinensis sp. nov. is proposed. The type strain is PJ-16^T (= CGMCC 1.13694^T= KCTC 72023^T).