Objective

This study aimed to isolate and characterize endophytic fungi associated with different tissues of Alocasia macrorrhizos and to evaluate their antibacterial and antioxidant potentials, supported by chemical profiling and in silico validation of bioactive metabolites.

Methods

Endophytic fungi were isolated from the leaves, corm, and roots of A. macrorrhizos and identified through morphological and molecular analyses. Ethyl acetate extracts of all isolates were screened for antibacterial activity using the disc diffusion method and for antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays. Bioactive extracts were analyzed by gas chromatography–mass spectrometry (GC–MS) to identify secondary metabolites. Molecular docking studies were performed against the bacterial target protein lactotransferrin to predict binding affinities and interaction patterns of selected compounds.

Results

Six endophytic fungi were isolated and identified as Curvularia sp. (AML-F1), Rhizopus sp. (AML-F2), Aspergillus spp. (AMC-F3 and AMC-F6), Paecilomyces sp. (AMR-F4), and Tulasnella sp. (AMC-F5). Molecular analysis confirmed Paecilomyces lecythidis (AMR-F4) and Aspergillus fumigatus (AMC-F6). Among all isolates, AMR-F4 and AMC-F6 showed the strongest antibacterial activity, with inhibition zones of 21.0 ± 1.52 mm and 22.0 ± 0.60 mm against Bacillus subtilis, and 17.7 ± 1.50 mm and 17.7 ± 0.31 mm against Staphylococcus aureus at 500 µg/disc, comparable to kanamycin. Both extracts also demonstrated notable antioxidant activity, with DPPH IC₅₀ values of 74.13 ± 1.49 µg/mL and 100.56 ± 0.16 µg/mL, and strong ferric ion reduction in the FRAP assay. GC–MS analysis identified 47 metabolites from AMR-F4 and 39 from AMC-F6. Molecular docking revealed higher binding affinities of selected compounds than kanamycin.

Conclusions

Alocasia macrorrhizos hosts bioactive endophytic fungi, particularly P. lecythidis and A. fumigatus, highlighting their potential as natural sources of antimicrobial and antioxidant agents.

Graphical Abstract