Description of Cobetia amphilecti sp. nov., Cobetia litoralis sp. nov. and Cobetia pacifica sp. nov., classification of Halomonas halodurans as a later heterotypic synonym of 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 specimens collected from the Gulf of Alaska and the Sea of Japan was subjected to taxonomic study. On the basis of 16S rRNA gene sequence analysis, the novel isolates were affiliated to the genusCobetia, sharing the highest sequence similarity of 99.3–99.9 % withCobetia marinaDSM 4741T. DNA–DNA hybridization experiments between and among the novel strains andC. marinaDSM 4741TandCobetia crustatorumJCM 15644Trevealed that the five strains represent three separate genospecies, which could be differentiated in their morphological, physiological and biochemical characteristics.Halomonas haloduransNBRC 15607Twas included in this study as it has recently been reported to exhibit high 16S rRNA gene sequence similarity toC. marinaDSM 4741T, and it showed a high DNA relatedness value of 96 % withC. marinaDSM 4741T, indicating that they belong to the same species. On the basis of phylogenetic analysis, DNA–DNA hybridization and phenotypic characterization, three novel species are proposed, namedCobetia amphilectisp. nov. (type strain KMM 1561T = NRIC 0815T = CCUG 49560T),Cobetia litoralissp. nov. (type strain KMM 3880T = NRIC 0814T = CCUG 49563T) andCobetia pacificasp. nov. (type strain KMM 3879T = NRIC 0813T = CCUG 49562T). It is also proposed thatHalomonas haloduransis a later heterotypic synonym ofCobetia marina, and emended descriptions of the genusCobetiaand the speciesCobetia marinaare provided.