三七中高产人参皂苷Rd真菌的鉴定

Identification of Fungi of High Yield Ginsenoside Rd Isolated from Panax notoginseng

从云南文山三七根茎上分离得到具有转化人参皂苷活性的真菌。采用的方法是:利用平板划线分离法,从三七根茎中分离纯化得到2株真菌,用该菌株对三七进行液态发酵。通过HPLC检测,对发酵前后皂苷变化进行分析,对两株真菌进行形态显微鉴定及ITS序列分析。结果表明,菌株形态及显微特征和产孢结构与木霉属一致,利用ITS序列与相关类群构建聚类树,确定实验2菌株ITS总长度为550bp,与长枝木霉Trichodermalongibrachiatum Rifai株菌(ATCC18648T、ATCC208859、DAOM167674、DAOM231259)仅在全ITS第134位点上发生间或缺失突变,鉴定2株真菌均为长枝木霉T.longibrachiatum。HPLC分析显示,菌株能够将三七中量多的大极性皂苷转化为小极性皂苷,并高产人参皂苷Rd。结论由此可以证明长枝木霉具有转化三七中皂苷的活性。

To obtain strains with positive activity of transforming ginsenoside from Panax notoginseng materials sampled in Wenshan of Yunnan. Methods ： Using plate streaking method, two fungi were isolated from samples of Pa- nax notoginseng roots. The samples of Panax notoginseng were fermented with the fungi, and the changes of saponins were determined by HPLC methods. Morphologic identification and ITS sequence analysis of the two fungi were car- ried out. Results： The two strains should belong to the genus Trichoderma based on the comparison and analysis of its morphology and characteristics of colony and sporulation structure. The ITS length of these strains were 550bp, and only one deletion mutation occasionally was taken place at the site 134 of ITS. It was indicated that these strains were highly similar to other strains of Trichoderma longibrachiatum Rifai （ATCC18648T, ATCC208859, DAOM167674, DAOM231259）. So these two strains were identified as T. longibrachiatum. Results from HPLC showed that the strains could efficiently convert big polarity ginseng saponins into small polarity ginseng saponins with high yielding ginsenoside Rd. Conclusion： T. longibrachiatum should possess activity for transforming ginseng saponins.