Molecular Characterization of Endophytic Fungi from the Leaves of Beruwas Laut (Scaevola taccada (Gaertn.) Roxb.) as Antibacterial Producer

Molecular Characterization of Endophytic Fungi from the Leaves of Beruwas Laut (Scaevola taccada (Gaertn.) Roxb.) as Antibacterial Producer Endophytic fungi live and develop in plant tissues, are symbiotic, and are host-plant friendly. These fungi generally produce secondary metabolites with anticancer, antiviral, or antibacterial properties. This study aims to identify endophytic fungi isolated from Beruwas laut leaves. The endophytic fungi were isolated from Potato Dextrose Agar (PDA), while the secondary metabolites were produced by fermentation on Maltose Yeast Broth medium, agitated for 18 days at 150 rpm. The chemical composition of the fungi was identified using TLC. The antibacterial activity was assessed against some pathogenic bacteria strains through agar diffusion and TLC- Bioautography methods, while molecular identification was conducted using PCR. The results revealed 16 chemical isolates from the endophytic fungi, among which IFDBL-15 exhibited the most potent antibacterial activity. Inhibitory zones of the isolates against Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 14990), Bacillus subtilis (ATCC 6633), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25923), and Salmonella typhi (NCTC 786) were 15.47, 14.52, 14.64, 14.10, 15.92, and 15.52 mm, respectively. The fermentation extract of the IFDBL-15 isolate contained flavonoids, alkaloids, anthraquinones, and saponins. TLC-Bioautography activity revealed four active spots. The spot that inhibited all test bacteria was identified as a flavonoid (Rf = 0.45). Molecular identification using ITS1 and ITS4 gene regions via Polymerase Chain Reaction showed that the IFDBL-15 isolate exhibited the closest relationship to the species Parengyodontium album with an identity match of 99.83%. IFDBL-15 endophytic fungi isolate has shown the potential to generate antibacterial metabolites and could be further explored as a drug lead.