目的 比较银杏内生真菌的抗菌活性,并对其抗菌活性成分进行分析。方法 采用组织分离法从健康银杏叶、枝条、果实等组织中分离、纯化内生真菌;以大肠杆菌、金黄色葡萄球菌、枯草芽胞杆菌、酿酒酵母、黑曲霉和根霉为抑菌指示菌,采用滤纸片和平板孔阱扩散法,对40株银杏内生真菌发酵液抗菌活性进行初筛和复筛;利用硅胶柱色谱、凝胶Sephadex LH-20柱色谱、制备型HPLC、薄层色谱(TLC)和HPLC-MS等方法,对抗菌活性较高的草酸青霉菌Penicillium oxalicum YXY009菌株的抗菌成分进行分析。结果 40株银杏内生真菌中,18株为不产孢真菌;产孢真菌中,青霉属和曲霉属为优势菌属,分别占总菌数的17.5%和15.0%;YXY009菌株发酵液的抑菌活性明显高于其他菌株,对酿酒酵母和根霉抑菌圈直径分别达到(22.35±1.32)和(23.60±0.83)mm;从YXY009菌株发酵液中分离得到抑菌活性有效成分,初步鉴定为毛果杨苷。结论 首次从银杏内生真菌代谢产物中分离出具有广谱抗菌活性的化合物毛果杨苷。

Objective To compare the antimicrobial activity of 40 endophyte strains from Ginkgo biloba and analyze the ingredients with antimicrobial activity. Methods Endophytic fungi inhabited in leaves, stems, and fruits of Ginkgo biloba were isolated. Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus niger and Rhizopus were used as indicators to do the microbial inhibition experiment. Forty strains antimicrobial activity were investigated by using filter paper method and flat hole well diffusion method. Silica gel column chromatography, Sephadex LH-20 column chromatography, preparative HPLC, TLC, and HPLC-MS were used to isolate, purificate and identify the antimicrobial components from the broth of Penicillium oxalicum YXY009. Results Eighteen strains produced sterile mycelia on PDA plates. Among the other strains, Penicillium spp. and Aspergillus spp. accounted for 17.5% and 15% of the total fungi. The strain with the highest antimicrobial activity was determined to be Penicillium oxalicum YXY009. The inhibiting zone diameters of the YXY009 strain reached (13.47 ±0.46), (22.35 ±1.32), and (23.60 ±0.83) mm against Bacillus subtilis, Saccharomyces cerevisiae, and Rhizopus, respectively. Conclusion An active compound POM was isolated from the fermentation broth of the strain P. oxalicum YXY009 and identified as 5-hydroxy-2-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl) oxan-2-yl] oxybenzoate for the first time.

国家自然科学基金面上项目(30270135);安徽省高等学校省级自然科学研究重点项目(KJ2013A049);国家级大学生创新创业训练计划项目(201510363072)