三种海藻内生真菌的分离及其抑菌活性研究

从烟台浅海处采集到的鼠尾藻、裙带菜、海带三种海藻表面消毒后用PDA培养基将内生真菌进行分离纯化,将纯化的内生真菌进行液体培养7d后离心,菌丝体烘干研磨后用无水乙醇提取,分别测定发酵液和菌丝体乙醇提取物对七种植物病原真菌的抑菌活性。结果表明:三种发酵液都至少对三种病原菌有大于50%的抑菌活性,裙带菜发酵液对六种病原菌都有大于50%的抑菌率,最高为78.8%,说明它们能产生广谱高效的胞外代谢产物;而菌丝体提取物的抑菌活性并不明显,说明三种海藻内生真菌产生的胞内代谢产物无明显的抑菌活性。

Study on Isolation and Antifungal Activities of Endophytic Fungi of Three Species of Alga

Three species of algae were collected from the coast of Yantai. After being surface disinfected, endophytic fungi were isolated with PDA medium. The purified endophytic fungi were cultivated in liquid medium for seven days. After centrifuging, mycelia were dried and grinded, then extracted with 95% alcohol. The antifungal activity of the fementation broch and ethanol extracts of mycelia on seven kinds of plant pathogenic fungi were assayed by means of mycelium growth rate. The results showed that all of the fermentation broth exhibited more than 50% antifungal activity against three kinds of botanical pathogenic fungi, especially the antifungal rates of the fermentation broch of the endophytic fungi isolated from Undaria pinnatifida on six kinds of plant pathogenic fungi were more than 50% even to the highest of 78.8%, which meaned they can produce extracellular metabolites with wide spectrum and high efficiency. But the antifungal activity of mycelia extracts is not remarkable, which meaned the intracellular metabolites of the three endophytic fungi were inactive.