Katayama Yoko, Hiraishi Akira, Kuraishi Hiroshi
Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan.
Japan Food Research Laboratories, Shibuya-ku, Tokyo 151, Japan.
Microbiology (Reading). 1995 Jun;141 ( Pt 6):1469-1477. doi: 10.1099/13500872-141-6-1469.
A facultatively chemolithotrophic thiocyanate-degrading bacterium, strain THI 011T, which was previously isolated from activated sludge and tentatively named Thiobacillus sp., was studied taxonomically and phylogenetically. This bacterium utilizes thiocyanate as sole energy source and the specific growth rate for chemolithoautotrophic growth with thiocyanate was 0.059 h-1. Molecular phylogenetic relationships of strain THI 011T to Thiobacillus versutus and members of the genus Paracoccus were elucidated by comparing 16S rRNA gene sequences. Binary sequence comparisons showed that strain THI 011T was most related to Paracoccus aminophilus, at a similarity level of 97.0%, and T. versutus was most similar to Paracoccus denitrificans, at a level of 99.1%. A neighbour-joining phylogenetic tree showed that strain THI 011T formed a cluster together with T. versutus and known species of the genus Paracoccus within the alpha-3 subclass of the Proteobacteria. DNA-DNA hybridization assays and phenotypic studies indicated that strain THI 011T differed from T. versutus and known species of the genus Paracoccus. On the basis of these results, we propose to classify strain THI 011T into a new species of the genus Paracoccus with the name Paracoccus thiocyanatus sp. nov. We also propose to transfer T. versutus to the genus Paracoccus and present an emended description of the genus.
从活性污泥中分离出的一株兼性化能自养硫氰酸盐降解细菌THI 011T，之前暂命名为硫杆菌属（Thiobacillus sp.），对其进行了分类学和系统发育学研究。该细菌利用硫氰酸盐作为唯一能源，以硫氰酸盐进行化能自养生长的比生长速率为0.059 h-1。通过比较16S rRNA基因序列，阐明了THI 011T菌株与韦氏硫杆菌（Thiobacillus versutus）及副球菌属（Paracoccus）成员之间的分子系统发育关系。二元序列比较表明，THI 011T菌株与嗜氨副球菌（Paracoccus aminophilus）关系最为密切，相似性水平为97.0%，而韦氏硫杆菌与反硝化副球菌（Paracoccus denitrificans）最为相似，相似性水平为99.1%。邻接法系统发育树显示，THI 011T菌株与韦氏硫杆菌以及变形菌门α-3亚类中的副球菌属已知物种形成一个聚类。DNA-DNA杂交分析和表型研究表明，THI 011T菌株与韦氏硫杆菌及副球菌属已知物种不同。基于这些结果，我们建议将THI 011T菌株归类为副球菌属的一个新物种，命名为嗜硫氰副球菌（Paracoccus thiocyanatus sp. nov.）。我们还建议将韦氏硫杆菌转移至副球菌属，并给出该属的修订描述。
