一株仙人掌植物内生真菌的分离鉴定及活性研究

Isolation,Identification and Bioactivity Screening of Endophytic Fungus Associated with Opuntia ficusindica Mill

从元江仙人掌的茎中分离到一株产广谱、高活性抑菌物质的内生真菌,经测定对细菌、植物病原真菌和皮肤致病真菌共21种病原微生物有较为明显的抑制作用。形态特征表明,该菌株与曲霉属(Aspergillus)中的土生曲霉(Aspergillus terreus)的特征基本一致,18S rDNA序列分析显示本菌株与土生曲霉的同源性高于99%,但该菌株的分生孢子梗上有明显的瘤状突起,不同于模式菌株。因此认为该菌株为土生曲霉的一个变种,命名为土生曲霉云南变种(Aspergillus terreusvar·yunnanensis)。并对其活性物质的生产条件进行了初步摸索,确定用查氏培养基为最佳种子培养基,PDA培养基为最佳发酵培养基,4d为最适发酵时间。

An endophytic fungus YM39661 producing broad-scope, high activities and antipathoganic substances was isolated from the stem of Opuntia ficusindica Mill , which has strong activity against twenty-one pathogenic microorganisms related to human and plants. The morphological characteristics of this strain are similar to Asperglilus terreus and the 18S rDNA sequence homology between strain YM39661 and Aspergillus terreus is more than 99%. But the conidiophore have obvious strumae, different to the model strain. The name Aspergillus terreus var. yunnanensis is proposed for strain YM39661. The fermentation conditions of this strain were investigated for the biosynthesis of bioactive metabolites.