银杏内生菌的分离及其抑菌活性筛选

从健康的银杏（Ginkgo biloba）茎和叶片中分离内生菌，结果从银杏叶和茎上共分离到内生真菌20株，其中9株来自银杏茎部，11株来自银杏叶部；内生放线菌23株，其中15株来自于银杏茎部，8株来自于银杏叶部；内生细菌15株，其中8株来自于银杏茎部，7株来自于银杏叶部。以金黄色葡萄球菌（Staphylococcus aureus）、枯草芽胞杆菌（Bacillus subtilis）、大肠埃希菌（Escherichia coli）、黑曲霉（Aspergillus niger）、酿酒酵母（Saccharomyces cerevisiae）作为指示菌，采用双层平板法对内生菌进行抑菌活性筛选，结果表明：20株内生真菌中有12株出现了抑菌活性，有抑菌活性菌株的比例为60.0%；23株内生放线菌中，仅3株出现了抑菌活性，有抑菌活性菌株的比例为13.0%；15株内生细菌中，有4株出现了抑菌活性，有抑菌活性菌株的比例为26.7%。

Isolation of endophytes from Ginkgo biloba and screening of their antimicrobial activity

Endophytes were isolated from healthy stems and leaves of Ginkgo biloba. The results showed that twenty endophytic fungus strains were isolated, including nine strains from the stems and eleven strains from the leaves; twenty-three endophytic actinomycete strains were isolated, including fifteen strains from the stems and eight strains from the leaves; fifteen endophytic bacteria strains were isolated, including eight strains from the stems and seven strains from the leaves. Five representative microorganisms Staphylococcus aureus, Escherichia coli,Bacillus subtilis, Aspergillus Niger and Saccharomyces cerevisiae were used as indicator microorganisms, and the method of double layer medium was used for screening the antimicrobial activity of endophytes. The results showed that twelve endophytic fungi with antimicrobial activity were obtained, accounting for 60.0% of the total isolated strains. Three endophytic actinomycetes with antimicrobial activity were obtained, accounting for 13.0% of the total isolated strains. Four endophytic bacteria with antimicrobial activity were obtained, accounting for 26.7% of the total isolated strains.