Ethyl Acetate Extracts Endophytic Fungi from the Medicinal Tree Fern Cyathea Contaminans (Hook) Copel with Antimicrobial Activity

Medicinal plants are a rich source of naturally occurring substances utilized in treating a wide range of diseases; as a result, they serve as the basis for discovering new drugs. Research has focused on the relationship between endophytic microorganisms and host plants, as they produce a variety of secondary metabolites with significant biological functions. This study aimed to extract the endophytic fungi from various plant parts, including the roots, barks, and leaves of the Cyathea contaminans (Hook) Copel, which was collected from Kerinci, Jambi, Indonesia. By employing direct planting and pouring techniques with fungal culture media, the fungi were separated from the roots, stems, hairs, and leaves of C. contaminans and grown on rice media. The secondary metabolite of the fungus was extracted using ethyl acetate. The extracts were then tested for antimicrobial activity using a disk diffusion assay against microbial pathogens Staphylococcus aureus ATCC29213, Escherichia coli ATCC25922, and Methicillin-Resistant Staphylococcus aureus (MRSA). This research yielded 19 endophyte fungi. In the antibacterial activity screening results, four fungal strains (CBK3, CDK1, CDK4, and CAK2) were active against S. aureus, MRSA, and E. coli, with an inhibition zone in the range of 15.08 ± 0.854 to 23.52 ± 0.87 mm. All active fungal isolates were identified molecularly. CBK3 and CDK1 were Paecilomyces subglobosus PP510226 and Penicillium citrinum PP510227, respectively, while CDK4 and CAK2 were comparable to Aspergillus terreus PP510229 and Aspergillus terreus PP510228. The four endophytic fungi of Cyathea contaminans may be a new source of antibacterial compounds.