Marinivirga aestuarii gen. nov., sp. nov., a member of the family Flavobacteriaceae, isolated from marine environments, and emended descriptions of the genera Hyunsoonleella, Jejuia and Pontirhabdus and the species Hyunsoonleella jejuensis, Jejuia pallidilutea and Pontirhabdus pectinivorans.

Two orange, rod-shaped, Gram-reaction-negative, aerobic bacterial strains devoid of flagella and gliding motility, designated strains KYW371(T) and KS18 were isolated from a seawater sample and a shellfish Ruditapes philippinarum, respectively, collected from Gwangyang Bay, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains belonged to the family Flavobacteriaceae; and that strain KYW371(T) was most closely related to Algibacter mikhailovii LMG 23988(T) (96.7 % sequence similarity), Pontirhabdus pectinivorans JC2675(T) (96.3 %), Postechiella marina M091(T) (95.6 %) and Hyunsoonleella jejuensis CNU004(T) (95.3 %). The 16S rRNA gene sequence similarity (98.8 %) and DNA-DNA relatedness (78.1 %) between strains KYW371(T) and KS18 indicated that these two strains represented a single species. The predominant cellular fatty acids of strain KYW371(T) were iso-C15 : 1 G, iso-C15 : 0, iso-C15 : 0 3-OH and iso-C17 : 0 3-OH. Flexirubin-type pigments were absent. MK-6 was the only isoprenoid quinone and the DNA G+C content was 34.8-36.6 mol%. Data from this taxonomic study employing a polyphasic approach suggested that the isolates represent a novel species in a new genus in the family Flavobacteriaceae, for which the name Marinivirga aestuarii gen. nov., sp. nov. is proposed. The type strain is KYW371(T) ( = KCTC 23449(T) = JCM 17452(T)), and an additional strain of the species is KS18 ( = KCTC 23128 = JCM 16845). Emended descriptions of the genera Hyunsoonleella, Jejuia and Pontirhabdus and the species Hyunsoonleella jejuensis, Jejuia pallidilutea and Pontirhabdus pectinivorans are also proposed.