Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
Biodiversity Center Kasetsart University (BDCKU), Bangkok 10900, Thailand.
Int J Syst Evol Microbiol. 2023 Jun;73(6). doi: 10.1099/ijsem.0.005948.
A polyphasic approach was used to describe two halophilic actinobacterial strains, designated LSu2-4 and RSe5-2, which were isolated from halophytes [ (L.) Dum. and (L.) L.] collected from Prachuap Khiri Khan province, Thailand. Comparative analysis of 16S rRNA gene sequences showed that strains LSu2-4 and RSe5-2 were assigned to the genus , with YIM 90109(99.2 and 99.2 % similarities, respectively) and DSM 44494(99.0 and 98.8 % similarities, respectively) being their closely related strains. Whereas the 16S rRNA gene sequence similarity between LSu2-4 and RSe5-2 was 99.4 %. Phylogenetic and phylogenomic analyses based on 16S rRNA gene and whole-genome sequences revealed that both strains clustered with YIM 90109 and DSM 44494. The average nucleotide identity (ANI) based on blast, ANI based on MUMmer and digital DNA-DNA hybridization (dDDH) relatedness values between the two strains and their closest type strains were below the threshold values for identifying a novel species. Morphological characteristics and chemotaxonomic features of both strains were typical for the genus by formed well-developed substrate mycelia and aerial mycelia which fragmented into rod-shaped spores. Whole-cell hydrolysates contained -diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were variously hydrogenated with 10 isoprene units and contained phosphatidylcholine in their polar lipid profiles. Major fatty acids were iso-C and 10-methyl C. analysis predicted that the genomes of LSu2-4 and RSe5-2 contained genes associated with stress responses and biosynthetic gene clusters encoding diverse bioactive metabolites. Characterization based on chemotaxonomic, phenotypic, genotypic and phylogenetic evidence demonstrated that strains LSu2-4 and RSe5-2 represents two novel species of the genus , for which the names sp. nov. (type strain LSu2-4=TBRC 16415=NBRC 115855) and sp. nov. (type strain RSe5-2=TBRC 16416=NBRC 115856) are proposed.
采用多相分类法描述了两株嗜盐放线菌菌株，分别命名为 LSu2-4 和 RSe5-2，它们从泰国巴蜀府采集的盐生植物[ (L.) Dum. 和 (L.) L.]中分离得到。16S rRNA 基因序列的比较分析表明，菌株 LSu2-4 和 RSe5-2 被分配到属，与 YIM 90109(分别为 99.2%和 99.2%的相似度)和 DSM 44494(分别为 99.0%和 98.8%的相似度)的亲缘关系最近。而 LSu2-4 和 RSe5-2 之间的 16S rRNA 基因序列相似度为 99.4%。基于 16S rRNA 基因和全基因组序列的系统发育和系统基因组分析表明，这两个菌株都与 YIM 90109 和 DSM 44494 聚类。基于 blast 的平均核苷酸同一性 (ANI)、基于 MUMmer 的 ANI 和两个菌株及其最接近的模式菌株之间的数字 DNA-DNA 杂交 (dDDH) 相关性值均低于确定新物种的阈值。两个菌株的形态特征和化学生物特征均为典型的属，形成了发育良好的基质菌丝和气生菌丝，气生菌丝断裂成杆状孢子。全细胞水解物含有 -二氨基庚二酸作为诊断二氨基酸。主要的类脂是磷脂酰胆碱。主要脂肪酸为 iso-C 和 10-甲基 C。基因组分析预测，LSu2-4 和 RSe5-2 的基因组包含与应激反应相关的基因和编码各种生物活性代谢物的生物合成基因簇。基于化学分类学、表型、基因型和系统发育证据的特征表明，菌株 LSu2-4 和 RSe5-2 代表属的两个新种，分别命名为 sp. nov. ( LS u2-4TBRC 16415=NBRC 115855)和 sp. nov. ( RS e5-2TBRC 16416=NBRC 115856)。
