School of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
Int J Syst Evol Microbiol. 2022 May;72(4). doi: 10.1099/ijsem.0.005352.
A non-spore-forming, motile and alkali-resistant actinobacterium, designated N2-46, was isolated from an alkaline soil sample collected from a cotton field in the Xinjiang region of PR China. Strain N2-46 formed creamy colonies on tryptone soy agar and managed to survive in extreme alkaline conditions at a pH value of 11. Strain N2-46 displayed the highest 16S rRNA gene similarity of 99.65 % to HY164, followed by F300 (99.61%) and T3246-1 (98.54 %). 16S rRNA-directed phylogenetic analysis showed that strain N2-46 was embedded in a subclade with F300 with a bootstrap value of 71.8 %. The phylogenetic tree based on core genes of genome sequences showed that strain N2-46 formed a unique subclade next to HY164 and F300 with a bootstrap value of 100 %. Digital DNA-DNA hybridization and the average nucleotide identity analyses showed that strain N2-46 displayed the highest values of 67.1 % (63.2-70.7 %) and 91.82 % with HY164, respectively. Comparative genomic analysis indicated that strain N2-46 and its three closest neighbours exhibited comparable distribution patterns in heavy metal resistance genes and biosynthetic gene clusters, while displaying distinctions probably related to ecological adaptation. MK-8(H) was identified as the predominant isoprenoid quinone. The main fatty acids were identified as iso-C and anteiso-C. Polar lipids are composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, mono and diacylated phosphatidylinositol dimannosides, as well as several uncharacterized polar lipid, glycolipid, and phospholipids. Genotypic and physiological analyses support the view that strain N2-46 (=JCM 34413=CGMCC 1.18819) should be classified as a novel species of the genus , for which the name sp. nov. is proposed.
一株非孢子形成、运动和耐碱放线菌，命名为 N2-46，从中国新疆棉田的碱性土壤样本中分离得到。菌株 N2-46 在胰蛋白胨大豆琼脂上形成奶油色菌落，并能在 pH 值为 11 的极端碱性条件下存活。菌株 N2-46 与 HY164 的 16S rRNA 基因相似度最高，为 99.65%，其次是 F300（99.61%）和 T3246-1（98.54%）。基于 16S rRNA 的系统发育分析显示，菌株 N2-46 与 F300 一起嵌入一个亚群，置信度为 71.8%。基于基因组序列核心基因的系统发育树显示，菌株 N2-46 与 HY164 和 F300 一起形成一个独特的亚群，置信度为 100%。DNA-DNA 杂交和平均核苷酸同一性分析表明，菌株 N2-46 与 HY164 的数值最高，分别为 67.1%（63.2-70.7%）和 91.82%。比较基因组分析表明，菌株 N2-46 及其三个最接近的近缘种在重金属抗性基因和生物合成基因簇的分布模式上具有可比性，同时表现出的差异可能与生态适应有关。MK-8（H）被鉴定为主要的类异戊二烯醌。主要脂肪酸为 iso-C 和 anteiso-C。极性脂由双磷脂酰甘油、磷脂酰甘油、磷脂酰肌醇、单酰化和二酰化磷脂酰肌醇二甘露糖苷以及几种未鉴定的极性脂、糖脂和磷脂组成。基因型和生理分析支持菌株 N2-46（=JCM 34413=CGMCC 1.18819）应归类为属的一个新种，因此建议使用新种名 sp. nov.。
