Demequina litorisediminis sp. nov., isolated from a tidal flat, and emended description of the genus Demequina

Abstract

A Gram-stain-positive, facultatively anaerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, GHD-1T, was isolated from a tidal flat sediment on the Yellow Sea, South Korea. It grew optimally at 30 °C, at pH 6.5-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain GHD-1T fell within the cluster comprising the type strains of species of the genus Demequina. Strain GHD-1T exhibited 16S rRNA gene sequence similarity values of 97.0-98.8 % to the type strains of Demequinaglobuliformis, D. salsinemoris, D. flava, D. sediminicola and D. activiva, and of 95.5-96.9 % to the type strains of the other species of the genus Demequina. The peptidoglycan type of strain GHD-1T is A4β based on l-Orn-l-Ser-l-Asp. It contained DMK-9(H4) and DMK-8(H4) as the major menaquinones and anteiso-C15 : 0, C16 : 0, iso-C16 : 0 and anteiso-C17 : 0 as the major fatty acids. The major polar lipids were phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified glycolipid. The DNA G+C content of strain GHD-1T was 68.7 mol%, and its DNA-DNA relatedness values with the type strains of five phylogenetically related species of the genus Demequina were 13-29 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain GHD-1T is separated from other recognized species of the genus Demequina. On the basis of the data presented, strain GHD-1T is considered to represent a novel species of the genus Demequina, for which the name Demequina litorisediminis sp. nov. is proposed. The type strain is GHD-1T (=KCTC 52260T=NBRC 112299T).