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

ABSTRACT

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.