A Gram-reaction-negative, aerobic, yellowish-orange-pigmented bacterial strain, designated JC2436(T), was isolated from tidal-flat sediment of Oi Island in Korea. Comparative 16S rRNA gene sequence analysis indicated its close affiliation to Vitellibacter vladivostokensis, with 96 % sequence similarity to the type strain. Cells grew with 2-6 % NaCl and at 10-41 degrees C. Orange flexirubin pigments were present. The major isoprenoid quinone was MK-6, the DNA G+C content was 48.7 mol% and the predominant fatty acids (>10 %) were iso-C(15 : 0) and iso-C(17 : 0) 3-OH. The data obtained from this polyphasic study support the classification of this isolate within a novel species in the genus Vitellibacter, for which the name Vitellibacter aestuarii sp. nov. is proposed. The type strain is JC2436(T) (=IMSNU 14137(T) =KACC 13727(T) =KCTC 22361(T) =JCM 15496(T)).