乌头内生真菌YLAC-3抗菌活性及其鉴定

Antimicrobial Activity of Aconitine-Producing Endophytic Fungus from Aconitum Leucostomum Worosch and Its Identification

为了筛选产乌头碱的内生真菌,采用组织分离法从白喉乌头根中分离内生真菌,用纸片扩散法检测内生真菌对4种指示菌的抑菌作用,通过薄层层析法(TLC)和高效液相色谱法(HPLC)检测真菌次生代谢产物中乌头碱,最后基于真菌形态特征和rRNA基因内转录间隔区(ITS)序列分析对菌株进行鉴定.结果显示,从白喉乌头根部共分离得到20株具有抑菌活性的内生真菌,其中菌株YLAC-3发酵液对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和白色念球菌均有较强的抑菌活性,且其发酵液中发现类似于乌头碱的化合物.说明菌株YLAC-3发酵液有较为广泛的抑菌活性,它可能产生乌头碱.菌株YLAC-3菌落、菌丝体和分生孢子的形态特征类似于曲霉菌属,与塔宾曲霉菌ITS序列(KP196359)的相似度为99%.初步鉴定该菌株为曲霉菌属有效发表种Aspergillus tubingensis的一个菌株.

The antimicrobial activity of endophytic fungi isolated the roots of Aconitum leucostomum to four indicators are detected through paper diffusion method.The extracts of the isolates were examined for the presence of aconitine by TLC and HPLC analysis,and the aconitine-producing endophytic fungi were identified by morphological characteristics and the ITS rRNA sequence analysis.As the results showed,20 endophytic fungi isolates showed antimicrobial activity against at least one of test strains,and the best results were obtained with the endophytic fungi strain YLAC-3.The TLC and HPLC results indicated that there was aconitine in the metabolic substances of YLAC-3 strain.Strain YLAC-3 was identified as Aspergillus tubingensis by its characteristic morphology and ITS sequence analysis.