Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India.
Syst Appl Microbiol. 2013 Feb;36(1):28-32. doi: 10.1016/j.syapm.2012.09.003. Epub 2012 Dec 21.
Five strains (JA325, JA389, JA473, JA563 and JA582) of Gram stain-negative, vibrioid to spiral shaped, phototrophic purple bacteria were isolated from solar salterns of India. All strains contained bacteriochlorophyll-a and carotenoids of the spirilloxanthin series as photosynthetic pigments. C(18:1)ω7c, C(18:1)ω7c 11-methyl and C(16:0) were the major fatty acids of all strains. Diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), ornithine lipid (OL), an unidentified phospholipid (PL), and an unidentified aminolipid (AL) were the major polar lipids of all the strains. According to 16S rRNA gene sequences, all strains clustered phylogenetically with the only species of the genus Rhodothalassium (99.8-99.3% sequence similarity) but only strains JA325 and JA563 were distinctly related (60+1.5% DNA-DNA hybridization [DDH]) to the type strain Rhodothalassium salexigens DSM 2132(T). However, the genotypic data of strains JA325 and JA563 was not supported because of a large number of phenotypic differences compared to the type strain, therefore, it is proposed that all five newly isolated strains were R. salexigens-like strains. In addition, phylogenetically, the Rhodothalassium clade represented a distinct lineage and formed a deep branch with less than 90% 16S rRNA gene sequence similarity to other orders of the Alphaproteobacteria, and characteristic phenotypic properties also distinguished these bacteria from other purple non-sulfur bacteria. Therefore, the novel family Rhodothalassiaceae fam. nov. and the novel order Rhodothalassiales ord. nov. are proposed for the distinct phyletic line represented by the genus Rhodothalassium.
从印度盐田分离到 5 株革兰氏阴性、弧菌样到螺旋形、光养紫色细菌，分别命名为 JA325、JA389、JA473、JA563 和 JA582。所有菌株均含有细菌叶绿素-a 和螺旋藻叶黄素系列的类胡萝卜素作为光合色素。所有菌株的主要脂肪酸均为 C(18:1)ω7c、C(18:1)ω7c 11-甲基和 C(16:0)。二磷脂酰甘油（DPG）、磷脂酰甘油（PG）、鸟氨酸脂（OL）、一种未鉴定的磷脂（PL）和一种未鉴定的氨基脂（AL）是所有菌株的主要极性脂。根据 16S rRNA 基因序列，所有菌株在系统发育上与唯一的 Rhodothalassium 属种（99.8-99.3%序列相似性）聚在一起，但只有 JA325 和 JA563 与模式株 Rhodothalassium salexigens DSM 2132（T）密切相关（60+1.5% DNA-DNA 杂交[DDH]）。然而，由于与模式株相比存在大量表型差异，菌株 JA325 和 JA563 的基因型数据不支持将其归入 Rhodothalassium 属。因此，建议将这 5 株新分离的菌株均归类为 Rhodothalassium salexigens 样菌株。此外，在系统发育上，Rhodothalassium 分支代表一个独特的谱系，与其他α变形菌目之间的 16S rRNA 基因序列相似性不到 90%，其特征表型特性也将这些细菌与其他紫色非硫细菌区分开来。因此，提出了新的科 Rhodothalassiaceae fam. nov. 和新的目 Rhodothalassiales ord. nov.，以代表 Rhodothalassium 属所代表的独特系统发育谱系。
