Identification and Bioactivities of Two Endophytic Fungi Fusarium fujikuroi and Aspergillus tubingensis from Foliar Parts of Debregeasia salicifolia

摘要

Endophytic fungi isolated from medicinal plants are important for production of antibiotics. They can produce secondary metabolites with diverse structures and activities. Debregeasia salicifolia is a plant of medicinal importance, and no report exists regarding isolation of endophytic fungi from it. This study was focused to isolate and identify culturable endophytic fungi from foliar parts of D. salicifolia and to determine their bioactivities. Molecular analysis resulted in identification of Fusarium fujikuroi, Aspergillus tubingensis and Rhizopus oryzae based on specific internal transcribed spacer primer (ITS1/ ITS4). Our analysis revealed that all fungal endophytes possess antibacterial activity against Gram-negative and Grampositive bacteria. Remarkably, Rhizopus oryzae at a concentration of 5 mg/mL efficiently restricted the growth of ATCC strain of E. coli in comparison with positive control ciprofloxacin. Rhizopus oryzae and F. fujikuroi at a concentration of 1000 μg/ml exhibited maximum antioxidant activity of 45% and 44%, respectively. They also showed antifungal activity ranging from 60 to 75% against Aspergillus flavus and Aspergillus niger. Our analysis of the fungal extracts through GC-MS indicated the presence of 21 compounds of diverse nature and structure. In conclusion, our study highlighted the potential of D. salicifolia to host a plethora of fungal endophytes that secrete potentially therapeutic bioactive metabolites.