Abstract

A Gram-stain-negative, facultative aerobic, non-flagellated, and rod-shaped bacterium, designated AR-13T, was isolated from a seawater on the East Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain AR-13T grew optimally at 30°C, at pH 7.0–8.0 and in the presence of 0–0.5% (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain AR-13T fell within the clade comprising the type strains of Arcobacter species, clustering coherently with the type strain of Arcobacter venerupis. Strain AR-13T exhibited 16S rRNA gene sequence similarity values of 98.1% to the type strain of A. venerupis and of 93.2–96.9% to the type strains of the other Arcobacter species. Strain AR-13T contained MK-6 as the only menaquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0, C18:1 ω7c, and summed feature 2 (iso-C16:1 I and/or C14:0 3-OH) as the major fatty acids. The major polar lipids detected in strain AR-13T were phosphatidylethanolamine, phosphatidylglycerol, and one unidentified aminophospholipid. The DNA G+C content was 28.3 mol% and its mean DNA-DNA relatedness value with the type strain of A. venerupis was 21%. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain AR-13T is separated from recognized Arcobacter species. On the basis of the data presented, strain AR-13T is considered to represent a novel species of the genus Arcobacter, for which the name Arcobacter acticola sp. nov. is proposed. The type strain is AR-13T (=KCTC 52212T =NBRC 112272T).

• Keywords: Arcobacter acticola; East Sea; novel species; polyphasic taxonomy; seawater