水仙内生真菌的分离及抑菌和抗肿瘤活性研究

目的 分离纯化水仙根茎中的内生真菌，并对分离得到的真菌进行抑菌和抗肿瘤活性筛选。方法 用组织分离法分离纯化水仙内生真菌后，以金黄色葡萄球菌Staphylococcus aureus、大肠杆菌Escherichia coli、绿脓杆菌Pseudomonas aeruginosa、肺炎克雷伯菌Klebsiella pneumoniae和人肝癌细胞HepG2作为受试对象，采用滤纸片法和MTT法对内生真菌菌株发酵液的醋酸乙酯提取物进行抑菌和抗肿瘤活性检测。结果 从水仙根茎共分离到18株内生真菌，各菌株发酵液的醋酸乙酯提取物对4种供试细菌和HepG2细胞都有抑制作用。在质量浓度10 mg/mL时，SX-R202和SX-S102对大肠杆菌和绿脓杆菌抑菌圈直径分别达到18 mm和20 mm；在质量浓度1 mg/mL时，SX-R201、SX-R202、SX-R203和SX-R204对HepG2细胞增殖抑制率分别为（86.0±1.1）%、（89.8±1.3）%、（62.9±0.9）%和（90.6±1.0）%。结合形态学特征和分子生物学鉴定确定SX-R201为尖孢镰刀菌属Fusarium sp. 菌株、SX-R202和SX-R203为青霉属Penicillium sp. 菌株、SX-R204和SX-S102为曲霉属Aspergillus sp. 菌株。结论 水仙内生真菌的抑菌和抗肿瘤效果明显，值得进一步研究。

Isolation of endophyte fungi in Narcissus tazetta var. chinensis and their antimicrobial and antitumor activities

Objectives To isolate endophytic fungi from the roots and stems of Narcissus tazetta var. chinensis, and to determine their antimicrobial and antitumor activities. Medthods After isolating the endophytic fungi, the antimicrobial activity from the isolated endophytic fungi was detected using filter paper method with Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae as indicator microorganisms. And the antitumor activity on HepG2 was detected by MTT assay. Results A total of 18 strains of the endophytic fungi were isolated. The ethyl acetate extracts of the fermentation broth had the significant antibiotic activity on almost all the indicator microorganisms, and had the apparent antitumor activity on HepG2. Among these, the antibiotic activity of strains SX-R202 and SX-S102 against E. coli and P. aeruginosa were the highest, with the inhibiting zone diameters of 18 and 20 mm, respectively, at the concentration of 10 mg/mL. And at the extracts concentration of 1 mg/mL, the inhibitory rates (IR) of strains SX-R201, SX-R202, SX-R203, and SX-R204 on HepG2 were (86.0 ± 1.1)%, (89.8 ± 1.3)%, (62.9 ± 0.9)%, and (90.6 ± 1.0)%. With the identification by morphology and molecular biology, strain SX-R201 was determined to belong to the genus Fusarium sp., and SX-R202 and SX-R203 to Penicillium sp., SX-R204 and SX-S102 to Aspergillus sp., respectively. Conclusion The results indicate that the endophytic fungi of N. tazetta var. chinensis are potential antimicrobial and antitumor resource, which deserves further studies.