Faculty of Science, Department of Biology, Mahasarakham University, Kham Riang, 44150, Maha Sarakham Province, Thailand.
Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Klong Luang, 12120, Pathumthani, Thailand.
Curr Microbiol. 2024 Jun 14;81(8):223. doi: 10.1007/s00284-024-03747-0.
Two endophytic actinobacteria, strains MK5 and MK7, were isolated from the surface-sterilized root of Jasmine rice (Oryza sativa KDML 105). These strains were aerobic actinobacteria with a well-developed substrate and aerial mycelia that formed spiral spore chains. The type strains that shared the high 16S rRNA gene sequence similarity with both strains were Streptomyces naganishii NBRC 12892 (99.4%), "Streptomyces griseicoloratus" TRM S81-3 (99.2%), and Streptomyces spiralis NBRC 14215 (98.9%). Strains MK5 and MK7 are the same species sharing a digital DNA-DNA hybridization (dDDH) value of 95.3% and a 16S rRNA gene sequence similarity of 100%. Chemotaxonomic data confirmed the affiliation of strains MK5 and MK7 to the genus Streptomyces. Strains MK5 and MK7 contained MK-9(H) as a major menaquinone; the whole-cell sugar of both strains was galactose and glucose. The strain MK5 shared 93.4% average nucleotide identity (ANI)-Blast, 95.5% ANI-MUMmer, 93% average amino acid identity, and 61.3% dDDH with S. spiralis NBRC 14215. The polyphasic approach confirmed that strain MK5 represents a novel species, and the name Streptomyces mahasarakhamensis sp. nov. is proposed. The type strain is MK5 (= TBRC 17754 = NRRL B-65683). Genome mining, using an in silico approach and searching biosynthesis gene clusters of strains MK5 and MK7, revealed that the genomes contained genes encoding proteins relating to plant growth promotion, bioactive compounds, and beneficial enzymes. Strains MK5 and MK7 could produce indole acetic acid and solubilize phosphate in vitro.
两株内生放线菌，菌株 MK5 和 MK7，从表面消毒的茉莉香米（Oryza sativa KDML 105）根部分离得到。这些菌株是好氧放线菌，具有发达的基质和气生菌丝，形成螺旋孢子链。与这两个菌株具有高 16S rRNA 基因序列相似性的模式菌株分别为链霉菌（Streptomyces naganishii）NBRC 12892（99.4%）、“灰色链霉菌”（Streptomyces griseicoloratus）TRM S81-3（99.2%）和螺旋链霉菌（Streptomyces spiralis）NBRC 14215（98.9%）。菌株 MK5 和 MK7 是同一物种，数字 DNA-DNA 杂交（dDDH）值为 95.3%，16S rRNA 基因序列相似度为 100%。化学分类数据证实菌株 MK5 和 MK7 属于链霉菌属。菌株 MK5 和 MK7 含有 MK-9（H）作为主要的menaquinone；两株菌的全细胞糖均为半乳糖和葡萄糖。菌株 MK5 与螺旋链霉菌 NBRC 14215 的平均核苷酸同一性（ANI）-Blast 为 93.4%，ANI-MUMmer 为 95.5%，平均氨基酸同一性为 93%，dDDH 为 61.3%。多相分类法证实菌株 MK5 代表一个新种，建议命名为玛哈沙拉堪链霉菌（Streptomyces mahasarakhamensis）sp. nov.。模式菌株为 MK5（=TBRC 17754=NRRL B-65683）。利用基于计算的方法对菌株 MK5 和 MK7 的基因组进行挖掘，发现基因组中包含编码与植物生长促进、生物活性化合物和有益酶相关蛋白的基因。菌株 MK5 和 MK7 能够在体外产生吲哚乙酸并溶解磷酸盐。
