Hiraishi Akira
Department of Environmental and Life Sciences, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580, Japan.
Int J Syst Evol Microbiol. 2017 Dec;67(12):5038-5045. doi: 10.1099/ijsem.0.002408. Epub 2017 Oct 16.
Two strains of thermotolerant phototrophic alphaproteobacteria, designated strains TUT3542 and TUT3581, were isolated from sediment mud and cyanobacterial mats in a geothermal spring in Japan, respectively, and taxonomically characterized. Both the strains were budding motile rods and were able to grow at 45 °C. Phototrophically grown cells of strains TUT3542 and TUT3581 produced pink and brownish red cultures, respectively, and showed in vivo absorption maxima at 800, 858-859 and 892-895 nm in the near infrared region, indicating the presence of a core reaction centre and peripheral pigment complexes with bacteriochlorophyll a. The intracytoplasmic membrane system was of the lamellar type parallel to the cytoplasmic membrane. 16S rRNA gene sequence comparisons showed that strains TUT3542 and TUT3581 had the highest similarity level to Rhodoplanes oryazae NBRC 109406 (99.6 %) and Rhodoplaneselegans AS130 (99.3 %), respectively. Genomic DNA-DNA reassociation studies revealed that strains TUT3542 and TUT3581 had hybridization levels of less than 62 and 56 % to the type strains of all established species of the genus Rhodoplanes, respectively. The G+C contents of genomic DNA were 67.7 mol% for strain TUT3542 and 70.4 mol% for strain TUT3581. Results of phenotypic studies showed that the two novel strains could be differentiated from any of the previously described Rhodoplanes species. Thus, the author proposes the names Rhodoplanes tepidicaeni sp. nov. for strain TUT3542 and Rhodoplanes azumiensis sp. nov. for strain TUT3581. The type strain of Rhodoplanes tepidicaeni is TUT3542 (=KCTC 15602=NBRC 112815) and the type strain of Rhodoplanes azumiensis is TUT3581 (=KCTC 15603=NBRC 112816).
从日本一个温泉的沉积泥和蓝藻席中分别分离出两株耐热光合α-变形菌，命名为TUT3542菌株和TUT3581菌株，并对其进行了分类学特征分析。这两株菌均为出芽运动的杆状菌，能够在45°C下生长。TUT3542菌株和TUT3581菌株光合生长的细胞分别产生粉红色和棕红色培养物，在近红外区域的体内吸收最大值分别为800、858 - 859和892 - 895 nm，表明存在核心反应中心和含有细菌叶绿素a的外周色素复合物。胞内膜系统为与细胞膜平行的层状类型。16S rRNA基因序列比较表明，TUT3542菌株和TUT3581菌株分别与稻田红平红球菌NBRC 109406（99.6%）和秀丽红平红球菌AS130（99.3%）具有最高的相似性水平。基因组DNA - DNA重结合研究表明，TUT3542菌株和TUT3581菌株与红平红球菌属所有已确立物种的模式菌株的杂交水平分别低于62%和56%。TUT3542菌株基因组DNA的G + C含量为67.7 mol%，TUT3581菌株为70.4 mol%。表型研究结果表明，这两株新菌株可与任何先前描述的红平红球菌物种区分开来。因此，作者提议将TUT3542菌株命名为温泉红平红球菌（Rhodoplanes tepidicaeni）新种，将TUT3581菌株命名为东条红平红球菌（Rhodoplanes azumiensis）新种。温泉红平红球菌的模式菌株为TUT3542（=KCTC 15602=NBRC 112815），东条红平红球菌的模式菌株为TUT3581（=KCTC 15603=NBRC 112816）。
