Loktanella variabilis sp. nov., isolated from a tidal flat

Abstract

Two Gram-negative, aerobic and rod-shaped or ovoid bacterial strains with different colony colours (greyish yellow and moderate orange), designated J-MR2-YT and J-MR2-O, were isolated from a tidal flat in the South Sea of South Korea. The two novel strains grew optimally at 35–37 °C. Strains J-MR2-YT and J-MR2-O showed no difference in their 16S rRNA gene sequences, and the mean DNA–DNA relatedness between them was 94 %. Phylogenetic trees based on 16S rRNA gene sequences revealed that strains J-MR2-YT and J-MR2-O clustered consistently with the type strains of Loktanella soesokkakensis , L. hongkongensis and L. cinnabarina , with which it exhibited 97.83–99.06 % sequence similarity. Sequence similarities to the type strains of the other recognized species of the genus Loktanella were 94.01–96.26 %. Both strains contained Q-10 as the predominant ubiquinone, C18 : 1ω7c as the major fatty acid and phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminolipid as the major polar lipids. The DNA G+C contents of strains J-MR2-YT and J-MR2-O were 68.1 and 68.4 mol%, respectively, and DNA–DNA relatedness values with the type strains of L. soesokkakensis , L. hongkongensis and L. cinnabarina were 19–37 %. Differential phenotypic properties, together with their phylogenetic and genetic distinctiveness, revealed that the two novel strains are separated from other species of the genus Loktanella . On the basis of the data presented, strains J-MR2-YT and J-MR2-O are proposed to represent a novel species of the genus Loktanella , for which the name Loktanella variabilis sp. nov. is proposed. The type strain is J-MR2-YT ( = KCTC 42074T = CECT 8572T).