Transcriptome and metabolome profiling reveal the inhibitory effects of food preservatives on pathogenic fungi

TL;DR

This study shows how common food preservatives inhibit harmful fungi and identifies specific genes and metabolites affected by one of them.

Contribution

The study reveals the antifungal mechanism of sec-butylamine through transcriptomic and metabolomic profiling of Aspergillus flavus.

Findings

Sec-butylamine, citric acid, and potassium sorbate significantly inhibited the growth of tested fungi at specific concentrations.

Transcriptomic analysis identified several downregulated genes in A. flavus following sec-butylamine exposure.

Metabolomic analysis showed changes in specific metabolites, including increased levels of some sugars and decreased levels of others.

Abstract

Sec-butylamine, potassium sorbate, and citric acid were selected as preservatives to investigate their inhibitory effects on common plant pathogens—Aspergillus flavus, Alternaria alternata, and Talaromyces funiculosus—as well as the inhibitory mechanism of sec-butylamine against A. flavus. The results showed that all three preservatives significantly inhibited the growth of the tested fungi. Under the experimental conditions, 0.6% sec-butylamine, 1.2% citric acid, and 0.2% potassium sorbate completely inhibited the growth of A. flavus. Similarly, 0.5% sec-butylamine, 1.0% citric acid, and 0.6% potassium sorbate completely inhibited A. alternata, while 1.0% sec-butylamine, 1.2% citric acid, and 0.8% potassium sorbate completely inhibited T. funiculosus. All three preservatives exhibited strong inhibitory activity against mycelial growth, with inhibition increasing alongside concentration under ex vivo conditions. To explore the inhibitory mechanism of sec-butylamine on A. flavus, transcriptomic and metabolomic analyses were conducted on A. flavus mycelia before and after treatment. The results revealed that key genes such as AFLA_053390, AFLA_121370, AFLA_024930, and AFLA_041970 were significantly downregulated following sec-butylamine exposure. Additionally, AFLA_002830 and AFLA_030450 also showed reduced expression levels. Metabolomic analysis identified several metabolites associated with sec-butylamine treatment. Compounds such as (3R)-4,4-dimethyl-2-oxotetrahydro-3-furanyl β-D-glucopyranoside (Com_5857_neg), trehalose (Com_3182_neg), D-glucosamine 6-phosphate (Com_4401_neg), and sucrose (Com_494_neg) were elevated, while D-gluconic acid (Com_9540_neg), D-glucose 6-phosphate (Com_723_neg), verbascose (Com_11501_neg), and D-(-)-fructose (Com_285_neg) were reduced after treatment. This study provides a reference for the practical application of food preservatives and lays a foundation for further research into their antifungal mechanisms.

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