Cobetia amphilecti sp. nov., Cobetia litoralis sp. nov. and Cobetia pacifica sp. nov., transfer of Halomonas halodurans NBRC 15607T to Cobetia marina and emended descriptions of the genus Cobetia and Cobetia marina.
ABSTRACT A group of five Gram-negative aerobic halotolerant non-pigmented bacteria isolated from shallow sediment samples and invertebrate specimen collected from the Gulf of Alaska and from the Sea of Japan was subjected to the taxonomic study. On the basis of 16S rRNA sequence analysis the novel isolates were affiliated to the genus Cobetia sharing the highest sequence similarities of 99.3-99.9% with the type strain of Cobetia marina DSM 4741T. The DNA-DNA hybridization experiments between novel strains themselves and towards Cobetia marina DSM 4741T and Cobetia crustatorum JCM 15644T revealed that five strains represent three separate genospecies, which could be differentiated in their morphological, physiological and biochemical characteristics. Strain Halomonas halodurans NBRC 15607T was included to the study as it has been recently reported to exhibit a high 16S rRNA gene sequence similarity to Cobetia marina DSM 4741T and it showed a high DNA relatedness value of 96% to C. marina DSM 4741T, indicating that they belong to the same species. On the basis of phylogenetic analysis, DNA-DNA hybridization and phenotypic characterization, three novel species, for which the names Cobetia amphilecti sp. nov. with the type strain KMM 1561T (=NRIC 0815T =CCUG 49560T), Cobetia litoralis sp. nov. with the type strain KMM 3880T (=NRIC 0814T =CCUG 49563T) and Cobetia pacifica sp. nov. with the type strain KMM 3879T (=NRIC 0813T =CCUG 49562T), are proposed.