Antifungal and anti-aflatoxigenic mechanisms of dielectric barrier discharge cold plasma on Aspergillus flavus spores

Abstract

Aspergillus flavus and its toxic aflatoxins secondary metabolites can cause a serious threat to food safety and public health. Recently, dielectric barrier discharge cold plasma (DBD-CP) has exhibited a high-efficiency decontamination ability on A. flavus spores, whereas its action mechanism remains unclear. This research investigated the mechanisms of antifungal and anti-aflatoxigenic properties of DBD-CP on A. flavus spores. Our results indicated that the ratios of cell apoptosis and necroptosis after DBD-CP treatment for 40 s were 37.0 % and 35.8 %, respectively. Moreover, the intracellular reactive oxygen species (ROS) were accumulated by DBD-CP, which triggered apoptosis by the metacaspase-dependent mitochondrial pathway and necroptosis by the RIP1/RIP3 necrosome, respectively. Besides, DBD-CP could inhibit aflatoxin B₁ production by regulating the expression of key genes (aflC, aflE and aflM) during the aflatoxin biosynthetic pathway. Hence, this work revealed new insight into the mechanisms of action by DBD-CP on A. flavus spores, providing a theoretical foundation for the application of DBD-CP in fungal inactivation and mycotoxin production.

Industrial relevance

This research revealed the antifungal mechanism by ROS-mediated apoptosis and necrosis, further exploring the anti-aflatoxigenic mechanism by inhibiting the expression of key genes in aflatoxin biosynthesis as well. These results contribute to the understanding of fungal inactivation and mycotoxin production by DBD-CP, accelerating the development of cold plasma in food decontamination.