Metagenomic insights of fungal diversity of peanuts under storage conditions and mitigation of aflatoxigenic fungi through competitive exclusion and phytochemicals

The present study was conducted to understand the diversity of fungal communities in peanuts using metagenomic analysis. The culture-dependent diversity analysis revealed the occurrence of aflatoxigenic fungi, Aspergillus flavus (A. flavus), and Aspergillus parasiticus (A. parasiticus). Further, to mitigate aflatoxigenic fungi, a systemic deployment of essential oils (EOs) along with an investigation involved studying a competitive exclusion bioassay utilizing atoxigenic Aspergillus flavus as a biocontrol agent. Gas chromatography-mass spectrometry (GC-MS) analysis of the results identified the primary constituents as Cuminaldehyde (EO3), Monarda citriodora essential oil containing thymol (EO8), linalool (EO14), and Terpinen-4-ol (EO16). Subsequently, the inhibition of aflatoxigenic fungi was assessed using a fumigant bioassay accomplished with an effective concentration noted at a dose of 2.5 μL–10 μL/107 cm3. The prominent inhibition of aflatoxin by atoxigenic A. flavus in competitive exclusion assay under co-culture conditions with aflatoxigenic A. flavus and A. parasiticus has been noteworthy. Hence, aflatoxin mitigation using the following approaches could be eco-friendly for the storage of peanuts under postharvest conditions. •Diversity analysis of peanuts by culture-independent (Metagenomics) and culture-dependant (Characterisation) approaches was studied.•Using essential oils as safe substitutes for synthetic fungicides offers a practical approach to decreasing aflatoxins in peanut seeds and securing food safety cost-effectively.•Biocontrol agents of native peanut systems are promising in control of Aflatoxin biosynthesis in A. flavus and A. parasiticus.