具抑菌活性连翘内生真菌的分离与鉴定

Isolation and identification of antimicrobial activity of endophytic fungi from Forsythia suspensa

摘要:

【目的】从药用植物连翘内生真菌中筛选抑菌活性菌株, 并对其主要活性成分进行检测分析。【方法】采用常规组织分离法分离内生真菌, 滤纸片法测定其发酵产物对3种指示细菌的抑菌活性。TLC、HPLC和HPLC-MS检测活性菌株代谢产物中连翘苷成分。根据形态学特征和ITS序列分析鉴定目的菌株。【结果】分离得到的24株内生真菌中抑菌圈直径超过10 mm的菌株, 发酵液组有11株(45.8%), 菌丝体组有19株(79.2%), 活性菌株主要集中在果实内生真菌中, 其中G5、G7和G10表现出较强的抑菌活性。从菌株G10的胞内产物中发现活性成分连翘苷, 将其鉴定为胶孢炭疽菌Colletotrichum gloeosporioides。【结论】连翘内生真菌是天然抗菌活性物质的重要筛选来源。

Abstract:

[Objective] The aim of this study was to screen antimicrobial fungal strains and to investigate the main active constituent of endophytic fungi isolated from the medicinal plant Forsythia suspensa. [Methods] Fungal endophytes were isolated with routine tissue separation methods, and the antimicrobial activities of their fermentation products were detected by filter paper method against 3 bacterial strains. Metabolites of active fungal strains were analyzed by TLC, HPLC and HPLC-MS methods. The final active fungal strains were identified based on morphological characteristics and ITS sequence analysis. [Results] Among the 24 isolated strains whose inhibition zone diameters more than 10 mm, group of fermentation broth had 11 (45.8%), group of mycelia had 19 (79.2%). Active fungal strains were mainly isolated from fruit, and G5, G7, G10 showed stronger antibacterial activities. Phillyrin was detected from the intracellular products of isolate G10, which was identified as Colletotrichum gloeosporioides. [Conclusion] The endophytic fungi in F. suspensa were important source for the natural antimicrobial substances.