浙贝母内生真菌Nectria sp.JZ6分泌抑菌活性代谢产物的初步研究

Nectria sp.JZ6是从浙贝母新鲜鳞茎中首次分离到的一株内生真菌,其发酵液具有抑菌活性。为建立该真菌稳定分泌抑菌活性成分的发酵体系,本研究利用单因素实验和正交实验确定了发酵培养基的配方并初步优化了发酵条件。结果表明,将活化后的菌种接种于改良查氏培养基(8%葡萄糖,0.5%蛋白胨,0.05%KCl,0.1%K2HPO4,0.15%MgSO4,pH6.5)中,28℃、150r/min振荡培养6d后获得的发酵液抑菌活性比优化前提高了26%。该发酵液经100℃水浴30min不失活,在pH1-5时抑菌活性相对稳定,其后逐渐减弱,并在pH9.0及以上时丧失。Nectriasp.JZ6发酵液的乙酸乙酯浸膏抑菌活性最强,对金黄色葡萄球菌、藤黄八叠球菌、枯草芽孢杆菌、绿脓杆菌和大肠杆菌的最低抑菌浓度(MIC)分别为0.625、0.625、1.25、1.25和1.25mg/mL。

A preliminary study on the antimicrobial activities of Nectria sp. JZ6, an endophytic fungus isolated from the bulbs of Fritillaria thunbergii

An endophytic fungus Nectria sp.was isolated from the fresh bulbs of Fritillaria thunbergii for the first time.The fungus can secrete antibacterial metabolites when cultured in CzapeK-DoX medium.In this study,the culture medium and fermentation conditions of the fungus were modified and optimized by single factor analysis and orthogonal tests.After being inoculated in the modified CzapeK-DoX medium(8% glucose,0.5% peptone,0.05% KCl,0.1% K2HPO4 and 0.15% MgSO4,pH 6.5),the fungus was cultured in a rotary shak...