PHYLOGENETIC INFERENCES AND TAXONOMIC CONSEQUENCES OF 16S RIBOSOMAL DNA-SEQUENCE COMPARISON OF CHROMOHALOBACTER-MARISMORTUI, VOLCANIELLA-EURIHALINA, AND DELEYA-SALINA AND RECLASSIFICATION OF VOLCANIELLA-EURIHALINA AS HALOMONAS-EURIHALINA COMB-NOV

The phylogenetic positions of the moderately halophilic bacteria Chrom ohalobacter marismortui, Volcaniella eurihalina, and Deleya salina wer e determined by PCR amplification of rRNA genes and direct sequencing, The resulting data were compared with data for other bacteria obtaine d 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 Halomo nas-Deleya branch, C. marismortui belongs in the family Halomonadaceae and has the characteristic 16S rRNA signatures defined for this famil y, including the distinctive cytosine residue at position 486 found in all members of the Halomonadaceae. V. eurihalina is closely related t o 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 rel ated to other species belonging to the Halomonas-Deleya complex, but i s 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. marismortu i, V. eurihalina, Halovibrio variabilis, and Paracoccus halodenitrific ans.