Antibacterial activities of fungal endophytes from Philippine endemic plant Dillenia philippinensis

• Main Authors: Moron, Llewelyn S., Española, Seraphim Marie S., Resurreccion, Maria Criselda C.
• Format: text
• Published: Animo Repository 2021
• Subjects: Endophytic fungi—Philippines; Dilleniaceae—Philippines; Dilleniaceae—Analysis; Antibacterial agents; Biology
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11539
• Institution: De La Salle University

Fungal endophytes play an important role as plant symbionts primarily because they synthesize biologically active substances that are potential sources to modern day drugs. In this study, 33 fungal endophytes were isolated from leaf specimens of the Philippine endemic tree Dillenia philippinensis. Morphological identification identified the fungal isolates belonging to eight different genera: Alternaria sp., Aspergillus sp., Geotrichum sp., Guignardia sp., Nigrospora sp., Paecilomyces sp., Pestalotiopsis sp., and Phialophora sp. Twenty-two representative fungal isolates were mass-produced and subjected to extraction of secondary metabolites using the liquid submerged fermentation set-up. The obtained crude extracts were tested for antimicrobial activities using the disk diffusion assay against Gram-positive bacteria: Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria: Escherichia coli and Multi-drug resistant Pseudomonas aeruginosa (MRPA). Results showed that crude extracts associated with D. philippinensis are good sources of secondary metabolites of which 73%, 68%, and 55% are respectively effective against S. aureus, E. coli and MRSA at a concentration of 10 mg/ml.