野葛内生真菌的分离、鉴定及体外细胞毒活性

目的:药用植物内生真菌是一类重要的微生物资源,其代谢产物有着广泛的生物学活性。该研究拟从野葛(Pueraria lobata(Willd.)Ohwi)中分离有细胞毒活性的内生真菌。方法:组织块改良法分离内生真菌;细胞毒活性测定采用Alamar blue法;结合形态学和分子生物学方法进行菌种鉴定。结果:获得的34株内生真菌中菌株KLBMP f0027对HepG2、HO-8910、NCI-H460、SGC-7901等细胞株均有显著活性,ID50分别为437.4、460.0、542.5、771.2。而且活性产物相对稳定,对温度、pH变化及蛋白酶不敏感。代谢过程研究显示菌株KLBMP f0027的活性产物合成与细胞生长属于部分耦联关系类型。形态学和ITS-rDNA序列分析鉴定菌株为Aspergillus ostianus strain KLBMP f0027。结论:野葛内生真菌A.ostianus strain KLBMP f0027可作为细胞毒活性候选菌株进行深入研究。

Isolation, Identification and Cytotoxic Activity in vitro of Endophytic Fungi from Pueraria lobata (Willd.) Ohwi

Objective:Endophytic fungi from medicinal plants are substantial microbial resource,which produce lots of metabolic compounds with a variety in biological activity.This study was to isolate endophytic fungi with cytotoxic activity from Pueraria lobata(Willd.) Ohwi.Method:The cytotoxic activity was detected by Alamar blue method.And strains with cytotoxic activity were identified by morphology together with similarity of internal transcribed spacer(ITS) sequence.Result:A total of 34 endophytic fungi were isolated and the strain KLBMP f0027 presented strong activity against cell lines including HepG2,HO-8910,NCI-H460,SGC-7901 with the ID50 437.4,460.0,542.5 and 771.2,respectively.The cytotoxic activity of the strain was relatively stable with no sensitivity to the changes of temperature,pH and proteases.And the biosynthesis of the metabolites with cytotoxic activity was partially associated with cell growth.The strain KLBMP f0027 was identified as Aspergillus ostianus strain KLBMP f0027,based on the morphological characteristics and sequence analysis of ITS-rDNA.Conclusion:A.ostianus strain KLBMP f0027 was deserved for cytotoxic activity research as an alternative resource.