Evaluating the bioactive and extracellular enzymatic potential of fungal endophytes isolated from the leaves of Asparagus densiflorus

The emergence of new pathogens and the increased rise in antimicrobial resistance warrants the search for novel sources of therapeutic agents. Even though secondary metabolites with notable biological activities have been isolated from medicinal plants, it has been shown that some of these metabolites originate from the endophytic fungi associated with the plants. The capabilities of endophytic fungi are not limited to the production of secondary metabolites; these microorganisms are able to produce industry-significant enzymes with broad applications. In this study, four (4) endophytic fungi isolated from Asparagus densiflorus leaves were screened for their antimicrobial, antioxidant, and extracellular enzymatic activities. The sequencing of the ITS region revealed that all four isolates belong to the phylum Ascomycota. The antimicrobial activity of the fungal endophytes' crude extracts was tested against Psuedomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, where MIC values ranged from 0.63 to 1.25 mg/ml. The ferric reducing antioxidant power assay revealed that the crude extracts demonstrated minimal antioxidant activity. All the isolates except AspL-3 were observed to possess laccase activity,;however, only AspL-3 possesses the protease activity. All the isolates were observed to possess peroxidase activity. The results obtained in this study further highlight that medicinal plants are an excellent source of fungal endophytes' significant biological and biotechnological potential.