Phylogenetic inferences and taxonomic consequences of 16S ribosomal DNA sequence comparison of Chromohalobacter marismortui, Volcaniella eurihalina, and Deleya salina and reclassification of V. eurihalina as Halomonas eurihalina comb. nov.

The phylogenetic positions of the moderately halophilic bacteria Chromohalobacter marismortui, Volcaniella eurihalina, and Deleya salina were determined by PCR amplification of rRNA genes and direct sequencing. The resulting data were compared with data for other bacteria obtained from 16S rRNA sequence databases. C. marismortui, V. eurihalina, and D. salina clustered phylogenetically within the gamma subclass of the Proteobacteria and are closely related to other species on the Halomonas-Deleya branch. C. marismortui belongs in the family Halomonadaceae and has the characteristic 16S rRNA signatures defined for this family, including the distinctive cytosine residue at position 486 found in all members of the Halomonadaceae. V. eurihalina is closely related to the type species of the genus Halomonas, Halomonas elongata, and we formally propose that V. eurihalina should be transferred to the genus Halomonas as Halomonas eurihalina comb. nov. The type strain of this species is strain F9-6 (= ATCC 49336). D. salina is not as closely related to other species belonging to the Halomonas-Deleya complex, but is more closely related to Halomonas elongata than to Deleya aquamarina, the type species of the genus Deleya. A polyphasic approach will be necessary to determine the natural taxonomic positions of the species belonging to the genera Halomonas and Deleya, as well as C. marismortui, V. eurihalina, Halovibrio variabilis, and Paracoccus halodenitrificans.