Plant-fungi interaction serves various insights for research. Therefore, the study aimed to isolate endophytic fungi from Allium cepa (onion) bulbs and Allium sativum (garlic) cloves to evaluate the biological activity of their metabolites. Remarkably, a heteromorphic strain of Fusarium oxysporum was successfully isolated and identified via Internal Transcribed Spacer (ITS) amplicon sequencing: the strain from onion was designated ACE (OR062575), and the one from garlic as ASE (OR062574). Morphologically, ACE spores exhibited no defined shape, whereas ASE produced oval and amygdaloid chlamydospores. The fungal extracts were evaluated using the free radical scavenging DPPH assay, antimicrobial disc diffusion method, and brine shrimp lethality bioassay. Notably, ASE demonstrated approximately 1.5 times higher 50% free radical inhibition compared to ACE. The ACE extract (80 µg/disc) showed significant antibacterial activity against Escherichia coli (18 mm) and Bacillus megaterium (16 mm), whereas ASE exhibited roughly half this activity at the same dose against E. coli and Pseudomonas aeruginosa. Interestingly, the cytotoxicity of ACE had a logarithmic 50% lethal dose of 0.44 µm/ml, and no significant difference was observed from the reference vincristine sulfate. These findings highlight the need for further investigation into how different Allium species influence fungal genetic variation and metabolic activities.
Hossain et al. (Fri,) studied this question.