具有抑菌活性的博落回内生真菌BLH34鉴定及发酵优化

Identification and Fermentation Optimization of an Endophytic Fungus BLH34 with Antibacterial Activity from Macleaya cordata

目的:鉴定一株来源于博落回植株叶片并具有抑菌活性的真菌菌株BLH34,对其发酵培养基配方进行优化。方法:采用牛津杯法研究了真菌菌株BLH34的抑菌活性;通过形态特征与ITS序列分析方法对其进行分类鉴定;通过单因素试验及正交试验设计优化其发酵培养基配方。结果:菌株BLH34对3种供试菌有抑菌活性,尤其对金黄色葡萄球菌的抑菌作用较强。菌株BLH34被鉴定为不整青霉Penicillium turbatum,其所产抑菌活性物质的最佳培养基配方为:5%可溶性淀粉、4%蛋白胨、0.06%NaNO_3和0.012%MgSO_4·7H_2O。结论:经过初步优化后菌株BLH34抑菌活性明显提高,为进一步分离纯化其次生代谢产物提供了基础。

Objective： To identify an endophytic fungus BLH34 isolated from the leaf of Macleaya cordata with antibacterial activity,and to optimize its fermentation medium. Methods： Antimicrobial activity of an endophytic fungus BLH34 was determined by the cylinder plate method. The morphological characteristics and internal transcribed spacer（ ITS） sequence were analyzed to identify the taxonomic position of the strain BLH34. The culture medium recipe was optimized by single factor and orthogonal experiment. Results： The results showed that the strain BLH34 had antimicrobial activity to the test strains,especially it showed significant inhibitory effect on Staphylococcus aureus. The strain BLH34 was identified as Penicillium turbatum,and the best culture medium recipe could be recognized as follows： 5% soluble starch,4% peptone,0. 06% NaNO_3,and 0. 012% MgSO_4·7H_2O. Conclusion： The antimicrobial activity of crude extract was significantly increased after optimization,which could provide a basis for further separation and purification of the antibacterial substances extracted from strain BLH34.