Department of Science Education, Jeju National University, Jeju 690-756, Republic of Korea.
Korea Research Institute of Bioscience and Biotechnology (KRIBB), PO Box 115, Yusong, Taejon, Republic of Korea.
Int J Syst Evol Microbiol. 2011 Aug;61(Pt 8):1933-1937. doi: 10.1099/ijs.0.022715-0. Epub 2010 Sep 10.
Two novel Gram-reaction-positive, rod-shaped actinobacterial strains, designated RP-B26(T) and RP-B30(T), were isolated from rhizosphere soil of a cliff-associated plant (Peucedanum japonicum Thunb.) which was collected from Mara Island, Republic of Korea. The colonies of the isolates were circular, smooth, convex and moderately yellow-light-yellow in colour. 16S rRNA gene sequence analysis revealed that the isolates belonged to the family Nocardioidaceae and formed two distinct sublineages within the radiation of the genus Nocardioides. 16S rRNA gene sequence similarity between the isolates was 98.2 %. The closest phylogenetic neighbours of strain RP-B26(T) were Nocardioides humi DCY24(T) and Nocardioides kongjuensis A2-4(T) with 97.4 and 97.0 % 16S rRNA gene sequence similarity, respectively, whereas 16S rRNA gene sequence similarities between strain RP-B30(T) and N. humi DCY24(T) and N. kongjuensis A2-4(T) were 96.5 and 96.0 %, respectively. Both of the isolates contained ll-diaminopimelic acid as the diagnostic diamino acid in the cell walls. The predominant menaquinone was MK-8(H(4)). The polar lipids were phosphatidylinositol and phosphatidylglycerol. The fatty acid profiles of the isolates were characterized by the presence of saturated, unsaturated, 10-methyl and hydroxyl fatty acids, with small amounts of branched fatty acids. The DNA G+C contents of strains RP-B26(T) and RP-B30(T) were 73.0 and 71.7 mol%, respectively. Levels of DNA-DNA relatedness between the isolates were 44.9 ± 1.5 % (thermal renaturation method) and 43.2 % (photobiotin-labelled method); the isolates showed low DNA-DNA relatedness values (<11 %) to the most closely related strain, N. humi KCTC 19265(T). On the basis of the phenotypic, genotypic and DNA-DNA hybridization data presented here, the isolates are considered to represent two novel species of the genus Nocardioides, for which the names Nocardioides ultimimeridianus sp. nov. (type strain RP-B26(T) = KCTC 19368(T) = DSM 19768(T)) and Nocardioides maradonensis sp. nov. (type strain RP-B30(T) = KCTC 19384(T) = DSM 19769(T)) are proposed.
两株新的革兰氏阳性、杆状放线菌菌株，分别命名为 RP-B26(T) 和 RP-B30(T)，从韩国马罗岛 cliff-associated 植物（Peucedanum japonicum Thunb.）的根际土壤中分离得到。分离物的菌落呈圆形、光滑、凸起，颜色为中度黄-浅黄色。16S rRNA 基因序列分析表明，这些分离物属于诺卡氏菌科，属于诺卡氏菌属的辐射范围内的两个不同的亚群。分离物之间的 16S rRNA 基因序列相似性为 98.2%。菌株 RP-B26(T) 的最接近的系统发育近邻是 Nocardioides humi DCY24(T) 和 Nocardioides kongjuensis A2-4(T)，其 16S rRNA 基因序列相似性分别为 97.4%和 97.0%，而菌株 RP-B30(T) 与 N. humi DCY24(T) 和 N. kongjuensis A2-4(T) 的 16S rRNA 基因序列相似性分别为 96.5%和 96.0%。两种分离物的细胞壁中均含有 ll-二氨基庚二酸作为诊断二氨基酸。主要的menaquinone 是 MK-8(H(4))。极性脂类是磷脂酰肌醇和磷脂酰甘油。分离物的脂肪酸谱特征是存在饱和、不饱和、10-甲基和羟基脂肪酸，以及少量支链脂肪酸。菌株 RP-B26(T) 和 RP-B30(T) 的 DNA G+C 含量分别为 73.0 和 71.7 mol%。分离物之间的 DNA-DNA 同源性水平为 44.9±1.5%（热复性法）和 43.2%（光敏生物素标记法）；分离物与最接近的菌株 N. humi KCTC 19265(T) 的 DNA-DNA 同源性值较低（<11%）。基于表型、基因型和 DNA-DNA 杂交数据，这些分离物被认为代表了诺卡氏菌属的两个新种，分别命名为 Nocardioides ultimimeridianus sp. nov.（模式菌株 RP-B26(T) = KCTC 19368(T) = DSM 19768(T)）和 Nocardioides maradonensis sp. nov.（模式菌株 RP-B30(T) = KCTC 19384(T) = DSM 19769(T)）。
