Arcobacter ebronensis sp. nov. and Arcobacter aquimarinus sp. nov., two new species isolated from marine environment

Two strains recovered from mussels (F128-2T) and sea water (W63T) were characterized as Arcobacter sp., but they could not be assigned to any known species using the molecular identification methods specific for this genus (16S rDNA-RFLP and m-PCR) and rpoB gene analysis. The 16S rRNA gene sequence similarity to the type strains of all Arcobacter species ranged from 92.2% to 96.7% with strain F128-2T, and from 94.1% to 99.4% with strain W63T, the most similar being A. bivalviorum (CECT 7835T) and A. defluvii (CECT 7697T), respectively. The phylogenetic analyses of 16S rRNA, and the concatenated sequences of gyrB, gyrA, rpoB, atpA and hsp60 genes confirmed that strains F128-2T and W63T belonged to two new lineages within the genus Arcobacter. Moreover, both strains showed differential phenotypic characteristics and MALDI-TOF mass spectra from all other Arcobacter species. Therefore, it has been demonstrated the existence of two new Arcobacter species and the proposed names are Arcobacter ebronensis (type strain F128-2T = CECT 8441T = LMG 27922T), and Arcobacter aquimarinus (type strain W63T = CECT 8442T = LMG 27923T).