湖泊放线菌SIIA-A16124的分类鉴定及基因组挖掘

Taxonomic identification and genome mining of actinobacteria strain SIIA-A16124 from lake

目的对湖泊放线菌SIIA-A16124进行分类鉴定和基因组挖掘。方法采用多相分类法对菌株的形态学、生理生化、细胞壁化学组分、16S r RNA基因序列进行测定和分类鉴定,采用基因组挖掘分析生物合成基因簇,经发酵培养、抗菌活性检测及活性产物质谱分析,推测其活性产物的化合物结构类别。结果菌株SIIA-A16124的16S r RNA基因与菌株Actinokineospora inagensis NRRL B-24050T同源性最高为99%;菌株SIIA-A16124在ISP3培养基上中等产孢和水解淀粉的特性与模式菌株存在明显差异;鉴定菌株SIIA-A16124为动孢菌Actinokineospora sp.,具有羊毛硫肽生物合成基因簇,其活性次级代谢产物属于羊毛硫肽类抗生素。结论首次发现动孢菌属放线菌具有生物合成羊毛硫肽类抗生素的能力。

Objective Taxonomic identification and genome mining of actinobacteria strain SIIA-A16124 were performed. Methods Polyphasic taxonomy based on morphology, physiological properties, cell wall composition, and the gene sequence analysis of 16S rRNA were adopted to determine the taxonomic status of strain SIIA-A16124. The prediction of bioactive secondary metabolites of the strain SIIA-A16124 was carried out by bioinformatic analysis, the determination of antibacterial activities, and ESI-MS analysis of the crude extract. Results The results showed that the similarity of 16S rRNA gene sequences between strain SIIA-16124 and the type strain Actinokineospora inagensis NRRL B-24050T was 99%. There existed obvious differences between the model strain and the strain SIIA-A16124 which produced spores in ISP3 medium and hydrolyzed starch. Strain SIIA-A16124 was identified as Actinokineospora sp., and the genome of this strain contained a novel lantibiotic gene cluster. In addition, the bioactive secondary product of strain SIIA-A16124 was preliminarily identified as lantibiotic. Conclusion The ability of lantibiotic biosynthesis was found for the first time in genus Actinokineospora.