Taxonomic study of the genus Salinicola: transfer of Halomonas salaria and Chromohalobacter salarius to the genus Salinicola as Salinicola salarius comb. nov. and Salinicola halophilus nom. nov., respectively.

We have carried out a polyphasic taxonomic characterization of the type strains of the species with the recently validated name Salinicola socius, together with two species that were phylogenetically closely related, Halomonas salaria and Chromohalobacter salarius. 16S rRNA gene sequence analyses showed that they constituted a coherent cluster, with sequence similarities between 98.7 and 97.7 %. We have determined the almost complete 23S rRNA gene sequences of these three type strains, and the percentage of similarity between them was 99.2-97.6 %. Phylogenetic trees based on the 16S rRNA and 23S rRNA gene sequences, obtained by using three different algorithms, were consistent and showed that these three species constituted a cluster separated from the other species of the genera of the family Halomonadaceae, supporting their placement in a single genus. All three species have ubiquinone 9 as the major respiratory quinone, and showed similar fatty acid and polar lipid profiles. The level of DNA-DNA hybridization between Salinicola socius DSM 19940(T), Halomonas salaria DSM 18044(T) and Chromohalobacter salarius CECT 5903(T) was 41-21 %, indicating that they are different species of the genus Salinicola. A comparative phenotypic study of these strains following the proposed minimal standards for describing new taxa of the family Halomonadaceae has been carried out. The phenotypic data are consistent with the placement of these three species in a single genus and support their differentiation at the species level. On the basis of these data we have emended the description of the species Salinicola socius and we propose to transfer the species Halomonas salaria and Chromohalobacter salarius to the genus Salinicola, as Salinicola salarius comb. nov. (type strain M27(T) =KCTC 12664(T) =DSM 18044(T)) and Salinicola halophilus nom. nov. (type strain CG4.1(T) =CECT 5903(T) =LMG 23626(T)), respectively.