| Abstrakt: |
Aspergillus flavus is a ubiquitous fungus that contaminates food, and its produced aflatoxin B1 (AFB1) is a potent carcinogen posing a significant threat to human health. This study investigated inhibitory effects of ajwain (Trachyspermum ammi) essential oil (AEO) on the growth and AFB1 production of A. flavus , and further elucidated its underlying action mechanisms. GC-MS analysis revealed a diverse chemical composition of AEO in which thymol (59.9%) is dominant compound. After screening the application method and optimizing fumigation conditions, AEO significantly inhibited the growth and AFB1 production of A. flavus (MFC = 30 μL/L). Moreover, AEO treatment of A. flavus at different developmental stages resulted in inhibited spore germination, hypobranching, impaired condition, structural disruption, and reduced AFB1 and ergosterol levels (p < 0.01). Metabolomics analysis revealed that AEO significantly affected 11 metabolic pathways in A. flavus , including inhibition of ergosterol biosynthesis and growth signaling molecules. Molecular biology research indicated that AEO downregulated the expression of multiple key genes in A. flavus , including global regulators (velB, veA, laeA, fluG, and Mtfa), growth and development regulators (brlA and abaA), AFB1 biosynthesis pathway-specific activator aflR and coordinator aflS, and key genes in the ergosterol biosynthesis pathway. In conclusion, AEO effectively inhibits A. flavus growth and aflatoxin production by modulating key pathways, involving downregulation of the Velvet complex, aflatoxin and ergosterol biosynthesis pathway. This research provides a theoretical basis for the development of novel natural antifungal agents and offers a new strategy for controlling aflatoxin contamination in food. [Display omitted] • Fumigation conditions were optimized to enhance the antifungal activity of AEO. • AEO inhibit A. flavus at different developmental stages. • Untargeted metabolomics analysis reveals the antifungal mechanism of AEO. • AEO can downregulate the gene expression of ergosterol and aflatoxin. [ABSTRACT FROM AUTHOR] |
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