Loktanella soesokkakensis sp. nov., isolated from the junction between the North Pacific Ocean and a freshwater spring

Abstract

A Gram-negative, aerobic, non-flagellated and rod-shaped or ovoid bacterial strain, designated DSSK1-5T, was isolated from the junction between the North Pacific Ocean and a freshwater spring at Jeju island, South Korea. Strain DSSK1-5T was found to grow optimally at 30 C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DSSK1-5T fell within the clade comprising Loktanella species, clustering consistently with the type strains of Loktanella hongkongensis and Loktanella cinnabarina, with which it exhibited 98.9 and 98.4 % sequence similarity values, respectively. Sequence similarities to the type strains of the other recognized Loktanella species were 94.0-96.2 %. Strain DSSK1-5T was found to contain Q-10 as the predominant ubiquinone and C18:1 ω7c as the major fatty acid. The major polar lipids of strain DSSK1-5T were identified as phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminolipid. The DNA G+C content of strain DSSK1-5T was determined to be 67.6 mol% and its mean DNA-DNA relatedness values with L. hongkongensis JCM 12479T and L. cinnabarina JCM 18161T were 19 and 23 %, respectively. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain DSSK1-5T is separated from other Loktanella species. On the basis of the data presented, strain DSSK1-5T is proposed to represent a novel species of the genus Loktanella, for which the name Loktanella soesokkakensis sp. nov. is proposed. The type strain is DSSK1-5T (= KCTC 32425T = CECT 8367T).