Agar plug diffusion was used to assess the endophytic fungus's antibacterial efficacy against pathogenic bacteria and yeast, as described by Jayatilake and Munasinghe (2020 (link)), with some modifications. Pure endophytic fungal cultures were grown on the PDA surface for three weeks at 28 °C. Fungal colony disks were then cut out (6 mm) under sterile conditions with a cork borer and deposited on Mueller Hinton Agar (MHA) or Sbouraud Dextrose Agar (SDA) previously inoculated with young pathogenic bacteria Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 10876, or Candida albicans ATCC 1024. A fungus-free PDA disk was used as a negative control. The Petri dishes were then placed in the refrigerator at 4 °C for 2 h to allow the antibacterial compounds to completely diffuse into the agar medium before being incubated at 37 °C for 24 h for bacteria and 48 h for yeast. The zones of inhibition that were formed around the agar plug were measured in order to evaluate the endophytic fungus ANT13 isolate's antimicrobial activity.