Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Int J Syst Evol Microbiol. 2014 Jun;64(Pt 6):2034-2040. doi: 10.1099/ijs.0.050005-0. Epub 2014 Mar 20.
A Gram-stain-negative, non-spore-forming, aerobic, oligotrophic bacterium (strain 262-7(T)) was isolated from a crack of white rock collected in the Skallen region of Antarctica. Strain 262-7(T) grew at temperatures between -4 and 30 °C, with optimal growth at 25 °C. The pH range for growth was between pH 6.0 and 9.0, with optimal growth at approximately pH 7.0. The NaCl concentration range allowing growth was between 0.0 and 1.0%, with an optimum of 0.5%. Strain 262-7(T) showed an unprecedented range of morphological diversity in response to growth conditions. Cells grown in liquid medium were circular or ovoid with smooth surfaces in the lag phase. In the exponential phase, ovoid cells with short projections were observed. Cells in the stationary phase possessed long tentacle-like projections intertwined intricately. By contrast, cells grown on agar plate medium or in liquid media containing organic compounds at low concentration exhibited short- and long-rod-shaped morphology. These projections and morphological variations clearly differ from those of previously described bacteria. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C(17 : 1)ω6c (28.2%), C(16 : 1)ω7c (22.6%), C(18 : 1)ω7c (12.9%) and C(15 : 0) 2-OH (12.3%). The G+C content of genomic DNA was 68.0 mol%. Carotenoids were detected from the cells. Comparative analyses of 16S rRNA gene sequences indicated that strain 262-7(T) belongs to the family Sphingomonadaceae, and that 262-7(T) should be distinguished from known genera in the family Sphingomonadaceae. According to the phylogenetic position, physiological characteristics and unique morphology variations, strain 262-7(T) should be classified as a representative of a novel genus of the family Sphingomonadaceae. Here, a novel genus and species with the name Polymorphobacter multimanifer gen. nov., sp. nov. is proposed (type strain 262-7(T) = JCM 18140(T) = ATCC BAA-2413(T)). The novel species was named after its morphological diversity and formation of unique projections.
一株革兰氏阴性、非孢子形成、需氧、贫营养的细菌（262-7(T) 株），从南极洲斯凯伦地区采集的白色岩石裂缝中分离得到。262-7(T) 株在-4 至 30°C 的温度范围内生长，最佳生长温度为 25°C。生长的 pH 值范围在 pH6.0 至 pH9.0 之间，最佳生长 pH 值约为 pH7.0。允许生长的 NaCl 浓度范围为 0.0% 至 1.0%，最佳为 0.5%。262-7(T) 株在应对生长条件时表现出前所未有的形态多样性。在液体培养基中生长的细胞在迟滞期呈圆形或卵圆形，表面光滑。在指数生长期，观察到具有短突起的卵圆形细胞。在静止期的细胞具有长触须状突起，错综复杂地交织在一起。相比之下，在琼脂平板培养基上或在含有低浓度有机化合物的液体培养基中生长的细胞表现出短杆状和长杆状形态。这些突起和形态变化明显不同于先前描述的细菌。泛醌 10 是主要的呼吸醌。主要脂肪酸为 C(17 : 1)ω6c（28.2%）、C(16 : 1)ω7c（22.6%）、C(18 : 1)ω7c（12.9%）和 C(15 : 0) 2-OH（12.3%）。基因组 DNA 的 G+C 含量为 68.0mol%。从细胞中检测到类胡萝卜素。16S rRNA 基因序列的比较分析表明，262-7(T) 株属于鞘氨醇单胞菌科，与鞘氨醇单胞菌科的已知属不同。根据系统发育位置、生理特性和独特的形态变化，262-7(T) 株应归类为鞘氨醇单胞菌科的一个新型属的代表。这里提出了一个新的属和种，名为多形变形杆菌属 Polymorphobacter multimanifer 属，sp. nov.（模式菌株 262-7(T) = JCM 18140(T) = ATCC BAA-2413(T)）。该新种以其形态多样性和独特突起的形成而得名。
