Metabolites profiling and bioactivity of Aspergillus-Penicilliumco-culture: Integrative GC-MS, LC-MS/MS, and in silico analysis for targeting Fusarium proliferatum in onion basal rot biocontrol

Onion basal rot, caused mainly by the soil-borne fungus Fusarium proliferatum , represents a serious and persistent disease problem of onion ( Allium cepa L.) worldwide. It results in severe yield reductions, impacting both quantity and quality of crop. This pathogen penetrates roots and results in damage of the basal plate of the onion, leading to decay and wilting. It is important to understand how to appropriately manage this disease, so its adverse effects can be minimized. Here, we examined the metabolites profile and bioactivity of co-culture system of Aspergillus ochraceus and Penicillium chrysogenum against Fusarium proliferatum , one of the main pathogens responsible for onion basal rot. By employing integrative analytical techniques such as GC-MS and LC-MS/MS, the metabolites profile from the co-culture extract was identified, particularly in the dichloromethane fractions. The fraction showed the highest antifungal activity with a minimum inhibitory concentration (MIC) of 0.39 mg/mL and showed the lowest cytotoxicity in brine shrimp assay. A molecular docking study on bioactive chemicals revealed that, among others, spirobrocazine A, palmitic acid, spathullin B, and citridone H were found to make a very high affinity with the cutinase enzyme from F. proliferatum , possibly leading to inhibition mechanisms. The results showed that fungal co-cultures have potential to produce bioactive compounds could be serve in production of biocontrol products with an eco-friendly application to counteract Fusarium infections in plants.