Arcobacter haliotis sp nov., isolated from abalone species Haliotis gigantea

A Gram-negative, aerobic, polar-flagellated and rod-shaped, sometimes slightly curved bacterium, designated MA5(T), was isolated from the gut of an abalone of the species Haliotis gigantea collected in Japan. Phylogenetic analyses based on 16S rRNA, gyrB, hsp60 and rpoB gene sequences placed strain MA5(T) in the genus Arcobacter in an independent phylogenetic line. Comparison of the 16S rRNA gene sequence of this strain with those of the type strains of the established Arcobacter species revealed A. nitrofigilis (95.1 %) as nearest neighbour. Strain MA5(T) grew optimally at 25 degrees C, pH 6.0 to 9.0 and in the presence of 2 to 5% (w/v) NaCl under both aerobic and microaerobic conditions. The predominant fatty acids found were summed feature 3 (iso-C-15:0 2-OH and/or C-16:1 omega 7c), C-12:0 3-OH and C-18:1 omega 7c. Menaquinone-6 (MK-6) and menaquinone-7 (MK-7) were found as the major respiratory quinones. The major polar lipids detected were phosphatidylethanolamine and phosphatidylglycerol. Strain MA5(T) could be differentiated phenotypically from the phylogenetic closest Arcobacter species by its ability to grow on 0.05% safranin and 0.01% 2,3,5-triphenyl tetrazolium chloride (TTC), but not on 0.5% NaCl. The obtained DNA G+C content of strain MA5(T) was 27.9 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic distinctiveness of MA5(T), this strain is considered to represent a novel species of the genus Arcobacter, for which the name Arcobacter haliotis sp. nov. is proposed. The type strain is MA5(T) (=LMG 28652(T)=JCM 31147(T)).