Antibacterial Activity of Endophytic Fungi Isolated from Pometia pinnata J. R. Forst & G. Forst Against Escherichia coli

The emerging of antimicrobial resistance become a global concern, encouraging researchers to find out alternative antimicrobial compounds. Endophytic fungi associated with medicinal plants become promising sources because of their ability to produce medical bioactive. This study aimed at bioprospecting fungal endophytes from an ethnobotanical medicinal plant, Pometia pinnata J. R. Forst & G Forst for their antimicrobial activity. Endophytic fungi isolated from leaf, stem, and root aseptically. Ten selected endophytes were cultured and then extracted using ethyl acetate. Screening antibacterial activity of ethyl acetate extract carried out by paper disk diffusion assay against Escherichia coli ATCC 25922. TLC-bioautography assay was used to study the type of secondary metabolite which has antibacterial activity. Identification of endophytic fungi based on morphology and ITS sequence using ITS1 and ITS4 primers. The result showed that two isolates have antibacterial activity but only one isolate exhibits strong antibacterial activity with a diameter of inhibition zone 21 mm. The isolate was identified as Aspergillus minisclerotigenes with 100% identity of the ITS sequence using BLAST software on NCBI. TLC assay indicated that ethyl acetate extract of A. minisclerotigenes contains alkaloids, phenols, flavonoids, and terpenoids while TLC bioautography showed that its phenolic compound appeared antibacterial activity.