Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov., isolated from coastal sediment

Two novel rod-shaped, Gram-stain-negative, aerobic and non-motile bacterial strains, designated M39 T and C2-7 T , were isolated from the coastal sediment of Xiaoshi Island, Weihai, PR China. Growth of strain M39 T occurred at 15–37 °C, at pH 6.0–9.0 and in the presence of 1.0–9.0 % (w/v) NaCl. Strain C2-7 T grew at 15–40 °C, at pH 6.0–8.0 and in the presence of 0.5–8.0 % (w/v) NaCl. Phylogenetic analysis based 16S rRNA gene sequences revealed that strains M39 T and C2-7 T belong to the phylum Bacteroidota . Based on the results of 16S rRNA gene sequence analysis, the closest relative of strain M39 T was Robiginitalea marina KCTC 92035 T (95.4 %), and the closest relative of strain C2-7 T was Algoriphagus namhaensis DPG-3 T (97.0 %). The percentage of conserved protein and average nucleotide identity values between strain M39 T and some species of the genus Robiginitalea were 66.9–77.6% and 69.3–71.0 %, respectively, while those between strain C2-7 T and some species of the genus Algoriphagus were 68.0–70.1% and 56.1–72.6 %, respectively. The major cellular fatty acids (>10 %) of strain M39 T consisted of iso-C 15 : 1 F, iso-C 15 : 0 and iso-C 17 : 0 3-OH, while those of strain C2-7 T were iso-C 15 : 0 and C 16 : 1 ω7 c /C 16 : 1 ω6 c . MK-6 was the only respiratory quinone that was compatible with the genus of strain M39 T . The predominant menaquinone of strain C2-7 T was MK-7. The major polar lipids of strain M39 T were phosphatidylethanolamine and glycolipids, and those of strain C2-7 T were phosphatidylethanolamine, one unidentified aminolipid and four unidentified lipids. The DNA G+C contents of strains M39 T and C2-7 T were 46.9 and 40.8 mol%, respectively. Based upon the results presented in this study, strains M39 T and C2-7 T represent novel species of the genera Robiginitalea and Algoriphagus , respectively, for which the names Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov. are proposed with the type strains M39 T (=MCCC 1H00498 T =KCTC 92014 T ) and C2-7 T (=MCCC 1H00414 T =KCTC 92027 T ).