Antimicrobial activity of endophytic fungi isolated from leaf and fruit of Eucommia ulmoides / 中草药

ABSTRACT

Objective: To isolate endophytic fungi from the leaves and fruits of Eucommia ulmoides and evaluate their antimicrobial activity.Methods: The endophytic fungi from the leaves and fruits of E. ulmoides were isolated by plate culture method, the antimicrobial activity was evaluated by standoff method, and the ability of producing bioactive compounds of E. ulmoides was investigated by HPLC. Results: A total of 52 endophytic fungi were isolated from segments of healthy the leaves and fruits E. ulmoides. Extract of two strains had a retention time identical to that of authentic chlorogenic acid. Eleven out of 52 strains exhibited antimicrobial activity to four or more fungal pathogens. The strain 29 (Alternaria SP.) showed maximum inhibition against Fusarium graminearum, and the radial growth inhibition was 82.6%. These endophytic fungi belonged to genus Alternaria, Niqrospora, and Dothideomycetes compared with the fungal sequence database at GenBank. Conclusion: Plenty of endophytic fungi from the leaves and fruits of E. ulmoides are found and 11 strains have antimicrobial activity. The antimicrobial activity of these endophytic fungi could be exploited in the biotechnological medicine and agricultural industry.