药用植物蕲艾内生真菌QA-6和QA-20次生代谢产物挖掘及抗水产病害菌活性研究

水产养殖病害和抗生素耐药性问题严重制约着我国水产养殖业的健康发展，造成了巨大的经济损失，迫切需要研究发现新型水产抗菌药。蕲艾是我国典型的药食两用性传统中药材植物，具有悠久的历史和鲜明的道地性，其内生真菌也可代谢产生结构丰富的生物活性物质。我们前期研究发现，两株蕲艾内生真菌亚细亚镰刀菌QA-6和高粱附球菌QA-20的发酵提取物对创伤弧菌、鳗弧菌和迟缓爱德华氏菌等多株水产病害菌表现出明显的抑制活性，且改变培养条件能影响以上两株真菌产生不同的代谢产物，进而影响其抗菌活性。本项目拟通过“一菌多产物”策略深入挖掘其代谢产物分子多样性，运用各种色谱学和波谱学方法分离鉴定结构新颖、抗水产病害菌活性显著的次生代谢产物，以期获得抗水产病害菌活性先导化合物并初步探讨其抑菌机制，为药用植物蕲艾内生真菌次生代谢产物在水产养殖领域中的开发利用提供一定的科学依据，为水产养殖业的健康可持续发展提供保障。

The problems of aquatic diseases and antibiotic resistance seriously restrict the healthy development of aquaculture industry and cause huge economic losses in China. Therefore, it is urgent to discover new compounds with potent antimicrobial activity against aquatic pathogens. Artemisia argyi is a typical edible Chinese traditional medicinal plant, which has a very long history and representative geoherbalism, and its endophytic fungi can produce many compounds with novel structures and prominent bioactivities. In our previous study, we have found that the crude extracts of two fungal strains Fusarium asiaticum QA-6 and Epicoccum sorghinum QA-20 exhibited potent antimicrobial activities against several aquatic pathogens Vibrio vulnificus, V. anguillarum, and Edwardsiella tarda. Moreover, the metabolism of these two fungal strains could be significantly affected by changing culture conditions, thus affect their antibacterial activities. This project intends to explore the molecular diversity of QA-6 and QA-20 by “OSMAC” strategy, increasing the rate of secondary metabolites with diverse skeletons and potent activity against aquatic pathogens under optimized conditions, which might provide lead compounds for novel anti-aquatic pathogenic drugs discovery. The antibacterial mechanism of the isolated potential compounds with application prospect will be further investigated, which would provide scientific basis for development and utilization of the secondary metabolites from A.argyi-derived fungi in aquaculture industry, and guarantee the healthy and sustainable development of the aquaculture industry.