Dobson S J, McMeekin T A, Franzmann P D
Department of Agricultural Science, University of Tasmania, Hobart, Australia.
Int J Syst Bacteriol. 1993 Oct;43(4):665-73. doi: 10.1099/00207713-43-4-665.
The genera Halomonas and Deleya, which constitute the family Halomonadaceae, are difficult to differentiate on the basis of phenotypic and chemotaxonomic attributes. DNA-rRNA hybridization studies have indicated that some Halomonas spp. have the same level of relationship to the type species of the genus Deleya as some Deleya spp. A phylogenetic analysis of the 16S rRNA sequences of seven members of the Halomonadaceae indicated that the members of the genera Halomonas and Deleya do not form separate monophyletic subgroups, confirming the lack of any phylogenetic support for retention of these taxa as separate genera. A phylogenetic analysis of the 16S rRNA sequence of Halovibrio variabilis confirmed that this species belongs in the Halomonadaceae. All of the members of the Halomonadaceae examined and Halovibrio variabilis possess a cytosine residue at position 486 (Escherichia coli numbering), which is an extremely rare attribute among the prokaryotes and has been reported in only one other species, Listonella anguillarum. Several other signature characteristics which define this group in the gamma subclass of the Proteobacteria are identified. The Jukes-Cantor distances between members of the family Halomonadaceae, including Halovibrio variabilis, range from 0.086 to 0.000 (the levels of similarity between the 16S rRNA sequences range from 92.6 to 100%). The members of the genera Halomonas, Deleya, and Halovibrio form a monophyletic group and share common chemotaxonomic and phenotypic characteristics. Subgroups containing members of the genera Halomonas, Deleya, and Halovibrio cannot be resolved on the basis of phylogenetic, chemotaxonomic, or phenotypic data. Our data indicate that the members of the genera Halomonas, Deleya, and Halovibrio should be united in a single genus.
盐单胞菌属（Halomonas）和德雷亚菌属（Deleya）构成了盐单胞菌科（Halomonadaceae），很难根据表型和化学分类学特征将它们区分开来。DNA-rRNA杂交研究表明，一些盐单胞菌属物种与德雷亚菌属的模式种之间的亲缘关系程度，与一些德雷亚菌属物种之间的亲缘关系程度相同。对盐单胞菌科7个成员的16S rRNA序列进行系统发育分析表明，盐单胞菌属和德雷亚菌属的成员并未形成独立的单系亚群，这证实了缺乏将这些分类单元保留为独立属的任何系统发育支持。对可变盐弧菌（Halovibrio variabilis）的16S rRNA序列进行系统发育分析证实，该物种属于盐单胞菌科。所检测的盐单胞菌科所有成员以及可变盐弧菌在第486位（大肠杆菌编号）都有一个胞嘧啶残基，这在原核生物中是极为罕见的特征，仅在另一个物种——鳗弧菌（Listonella anguillarum）中报道过。还确定了其他几个在变形菌纲γ亚类中定义该类群的标志性特征。包括可变盐弧菌在内的盐单胞菌科成员之间的朱克斯-坎托距离在0.086至0.000之间（16S rRNA序列之间的相似性水平在92.6%至100%之间）。盐单胞菌属、德雷亚菌属和盐弧菌属的成员形成一个单系群，并具有共同的化学分类学和表型特征。基于系统发育、化学分类学或表型数据，无法区分包含盐单胞菌属、德雷亚菌属和盐弧菌属成员的亚群。我们的数据表明，盐单胞菌属、德雷亚菌属和盐弧菌属的成员应合并为一个属。
