Ruegeria Marisflavi Sp. Nov. and Ruegeria Aquimaris Sp. Nov., Isolated from Seawater of the Yellow Sea

Two novel Gram-stain-negative, aerobic, non-motile and rod-shaped bacteria, designated as WL0004(T) and XHP0148(T), were isolated from seawater samples collected from the coastal areas of Nantong and Lianyungang, PR China, respectively. Both strains were found to grow at 10-42 degrees C (optimum, 37 degrees C) and with 2.0-5.0 % (w/v) NaCl (optimum, 3.0 %). Strain WL0004(T) grew at pH 6.0-9.0 (optimum, pH 7.0-8.0), while XHP0148(T) grew at pH 6.0-10.0 (optimum, pH 7.0-8.0). The major cellular fatty acids (>10 %) of both strains included summed feature 8 (C-18 : 1 omega 6c and/or C-18 : 1 omega 7c). In addition, strain WL0004(T) contained 11-methyl C-18 : 1 omega 7c and strain XHP0148(T) contained C-12 : 0 3-OH. The respiratory quinone of both strains was ubiquinone-10. The G+C content of genomic DNA of strains WL0004(T) and XHP0148(T) were 62.5 and 63.0 mol%, respectively. Strains WL0004(T) and XHP0148(T) showed the highest 16S rRNA gene sequence similarity to Ruegeria pomeroyi DSS-3(T) (99.4 and 99.0 %, respectively), and the 16S rRNA gene-based phylogenetic analysis indicated that the two strains were closely related to members of the genus Ruegeria. The average nucleotide identity and digital DNA-DNA hybridization values among the two strains and type strains of the genus Ruegeria were all below 95 and 70 %, respectively, and the phylogenetic tree reconstructed from the bac120 gene set indicated that the two strains are distinct from each other and the members of the genus Ruegeria. Based on this phenotypic and genotypic characterization, strains WL0004(T) (=MCCC 1K07523(T)=JCM 35565(T)=GDMCC 1.3083(T)) and XHP0148(T) (=MCCC 1K07543(T)=JCM 35569(T)=GDMCC 1.3089(T)) should be recognized as representing two novel species of the genus Ruegeria and the names Ruegeria marisflavi sp. nov. and Ruegeria aquimaris sp. nov. are proposed, respectively.