泰山黄精内生真菌的分离鉴定及抑菌活性研究

目的 研究泰山黄精内生真菌的分布及其多样性,并筛选具有抑菌活性的内生真菌.方法 采用平板分离法分离黄精内生真菌,采用滤纸片扩散法测试黄精内生真菌培养物抗耐药菌活性,同时采用分子生物学方法对筛选出的活性菌株进行鉴定.结果 从泰山野生黄精的根、茎、叶和果实中共分离出32株内生真菌,分属于7个属,分布最广的类群是镰刀菌属Fusarium sp.,占总菌株的31.3％,其次是不产孢真菌Sterile mycelia (28.1％)和链格孢属Alternaria sp.(21.9％).各组织中内生真菌的分布存在一定的组织差异性,根中内生真菌的分离率最高,茎和叶中次之,果实中最少.共有来自5个属的14株内生真菌至少对1种供试菌株有抗菌活性,其中8株具有广谱抗耐药菌活性.对活性最强、抑菌谱最广的不产孢菌株HJG-10进行分子生物学鉴定,将其确定为裂褶菌Schizophyllum commune.结论 泰山黄精中蕴含着大量具有抑菌活性的内生真菌,为寻找和开发新型抑菌生物制剂开辟了一条新途径.

Isolation and identification of endophytic fungi from Polygonatum sibiricum in Mountain Tai and study on their antimicrobial activity

Objective To study the diversity of endophytic fungi from Polygonatum sibiricum growing in Mountain Tai and screen the endophytic fungi with antimicrobial activity. Methods Endophytic fungi were isolated with the conventional method and their antimicrobial activities against tested microorganisms were investigated by using the paper disc method. The endophytic fungi with higher antimicrobial activity were identified based on ITS sequence analysis. Results A total of 32 endophytic fungi strains were isolated from the roots, stems, leaves, and fruits of P. sibiricum belonging to seven genera. The most widely distributed genera is Fusarium sp. (31.3%), followed by Sterile mycelia (28.1%) and Alternaria sp. (21.9%). Some endophytic fungi showed a certain degree of tissue preference. More species and strains were isolated from the roots, followed by those in the stems and leaves but those in the fruits were the least. Fourteen strains from five genera with the antimicrobial activity were obtained, among which eight strains showed broad-spectrum antimicrobial activity. The strain HJG-10 with the highest antimicrobial activity was determined to be Schizophyllum commune, according to its molecular analysis. Conclusion The research not only provides the theoretical basis for developing and utilizing the resources of endophytic fungi in P. sibiricum in Mountain Tai but also shows a new path for searching novel antimicrobial resource.