Loktanella aestuariicola sp. nov., an alphaproteobacterium isolated from a tidal flat.

Abstract

A Gram-stain negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, J-TF4(T), which was isolated from a tidal flat in the South Sea of South Korea, was characterized taxonomically. Strain J-TF4(T) was found to grow optimally at 30 °C, at pH 7.0-8.0 and in presence of 2.0-3.0% (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain J-TF4(T) fell within the clade comprising the type strains of Loktanella species, clustering with the type strains of Loktanella cinnabarina, Loktanella hongkongensis, Loktanella soesokkakensis, Loktanella pyoseonensis and 'Loktanella variabilis' showing sequence similarity values of 97.2-98.4%. The strain exhibited 16S rRNA gene sequence similarity values of 94.1-95.4% to the type strains of the other Loktanella species. Strain J-TF4(T) was found to have Q-10 as the predominant ubiquinone and C(18:1) ω7c as the major fatty acid. The major polar lipids of strain J-TF4(T) were identified as phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and an unidentified aminolipid. The DNA G+C content of strain J-TF4(T) was determined to be 67.9 mol% and its mean DNA-DNA relatedness values with the type strains of five phylogenetically related Loktanella species were 17.7-23.3%. Differential phenotypic properties, together with the phylogenetic and genetic data, demonstrate that strain J-TF4(T) is separated from other Loktanella species. On the basis of the data presented, strain J-TF4(T) is considered to represent a novel species of the genus Loktanella, for which the name Loktanella aestuariicola sp. nov. is proposed. The type strain is J-TF4(T) (=KCTC 42135(T)=NBRC 110408(T)).