Isolation of endophytic fungi with antibacterial activity from medicinal plant Jatropha multifida L.

The need for new antimicrobial agents is driven by the worldwide health crisis caused by bacteria resistant to existing ones. Jatropha multifida L. is an ethnomedicinal plant widely used in West Sumatra, Indonesia. This research examines the antibacterial properties of compounds extracted from the endophytic fungi isolated from the plant’s roots, barks, and leaves, including identifying proficient fungi and their secondary metabolites’ LC/MS-MS profiles. Fourteen endophytic fungi were successfully isolated from different parts using direct planting and pouring methods. Following 4–6 weeks of cultivation in rice medium, the fungus isolate was extracted using ethyl acetate. The antibacterial activity of each ethyl acetate extract of the fungus was evaluated using the Kirby–Bauer diffusion method against Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus. The JMB4 and JMD3 isolates of endophytic fungi showed promise as an antibacterial agent and showed notable inhibitory diameters, according to the inhibition zone measurement results. At a concentration of 5%, JMB4 and JMD3 exhibited inhibition zones measuring 21.79 ± 0.31 mm and 23.19 ± 0.58 mm against S. aureus and 22.55 ± 0.7 mm and 13.37 ± 0.77 mm against MRSA, respectively. The fungi JMB4 and JMD3 have been classified as Fusarium incarnatum and Fusarium oxysporum through macroscopic, microscopic, and molecular identification methods. Liquid chromatography–mass spectrometry/mass spectrometry analysis of the JMD3 extract revealed that the predominant peak corresponded to the molecular formula C22H31NO4 and was tentatively identified as equisetin. The findings demonstrate that J. multifida L. plants harbor endophytic fungi that can synthesize antibacterial compounds. Additional research is required to determine the antibacterial compounds responsible. Those compounds will promote the advancement of novel antibacterial agents.