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.