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【目的】以对叶百部块根为材料分离内生放线菌,并对分离菌株进行分类、抗菌活性和次级代谢产物合成基因研究。【方法】样品经过严格的表面消毒,选用4种培养基分离百部内生放线菌;分离菌株通过形态观察和16S rRNA序列分析进行分类鉴定;采用琼脂移块法测试分离菌株的抗菌活性;通过PCR检测分离菌株的PKS/NPRS和卤化酶基因;使用HPLC-UV/VIS-ESI-MS/MS分析发酵产物。【结果】从6个样品中获得18株内生放线菌,分属链霉菌属(Streptomyces)、小单孢菌属(Micromonospora)、假诺卡氏菌属(Pseudonocardia)和甲基杆菌属(Methylobacterium)。分离菌株绝大部分具有抗菌活性和次级代谢产物合成基因,其中13株对耐药金黄色葡萄球菌和/或绿脓杆菌有拮抗活性,17株具有PKS/NRPS基因,8株菌具有卤化酶基因,且卤化酶阳性代表菌株的发酵产物具有抗细菌活性和卤代化合物特征。【结论】百部作为一种传统中药,其内生放线菌以链霉菌和小单孢菌为主,在次级代谢产物合成方面具有很好的潜力,可作为一类重要微生物资源进行活性产物开发。
【OBJECTIVE】 Endophytic actinomycetes were isolated from the root of leaves of Radix Aconiti Lateralis. The isolates were classified, antibacterial activity and genes of secondary metabolites were synthesized. 【Method】 The samples were sterilized by strict surface. Four kinds of culture medium were used to isolate endophytic actinomycetes. The isolated strains were identified by morphological observation and 16S rRNA sequence analysis. The antibacterial activity of the isolated strains was tested by agar block method. The PKS / NPRS and halogenase genes of the isolates were tested by PCR; the fermentation products were analyzed using HPLC-UV / VIS-ESI-MS / MS. 【Result】 Twenty-eight strains of endophytic actinomycetes were obtained from six samples, belonging to the genera Streptomyces, Micromonospora, Pseudonocardia and Methylobacterium Methylobacterium). Most of isolates had antimicrobial activity and secondary metabolite biosynthesis genes. Among them, 13 strains had antagonistic activity against drug-resistant Staphylococcus aureus and / or Pseudomonas aeruginosa, 17 strains had PKS / NRPS gene and 8 strains had halogenase Gene, and the fermentation product of the halogenase-positive strain has antibacterial activity and halogenated compound characteristics. 【Conclusion】 As a kind of traditional Chinese medicine, the endophytic actinomycetes from Strelitziaceae are mainly Streptomyces and Micromonospora, which have good potential in the synthesis of secondary metabolites and can be used as a kind of important microbial resources for their activity Product development