Mariniflexile soesokkakense sp. nov., a member of the family Flavobacteriaceae isolated from the junction between the North Pacific Ocean and a freshwater spring, and emended description of the genus Mariniflexile

Abstract

A Gram-negative, non-flagellated and rod-shaped bacterial strain able to move by gliding, designated RSSK-9(T), was isolated from the junction between the North Pacific Ocean and a freshwater spring at Jeju island, South Korea. Strain RSSK-9(T) was found to grow optimally at 30°C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain RSSK-9(T) fell within the clade comprising Mariniflexile species. Strain RSSK-9(T) exhibits 16S rRNA gene sequence similarity values of 97.1-98.8% to the type strains of Mariniflexile species and of less than 95.6% sequence similarity to the type strains of the other recognized species. Strain RSSK-9(T) was found to contain MK-6 as the predominant menaquinone and iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and iso-C15:0 3-OH as the major fatty acids. The major polar lipids of strain RSSK-9(T) were identified as phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain RSSK-9(T) was determined to be 34.6mol% and its DNA-DNA relatedness values with the type strains of the four Mariniflexile species were in the range 11-28%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain RSSK-9(T) is separate from other Mariniflexile species. On the basis of the data presented, strain RSSK-9(T) is considered to represent a novel species of the genus Mariniflexile, for which the name Mariniflexile soesokkakense sp. nov. is proposed. The type strain is RSSK-9(T) (=KCTC 32427(T)=CECT 8369(T)). An emended description of the genus Mariniflexile is given.