Ferrous Sulfate-Induced Ferroptosis-like Death for Enhanced Cold Plasma Inactivation of Sublethally Injured Listeria monocytogenes

Cold plasma (CP) is an emerging non-thermal decontamination technology with strong oxidative antimicrobial activity; however, sublethally injured Listeria monocytogenes may survive and recover, limiting its food safety effectiveness. This study developed a CP-FeSO 4 strategy to induce ferroptosis-like cell death in L. monocytogenes . The combined treatment (CP: 50 W, 4 min; FeSO 4 : 50 μM) achieved >99.99% inactivation, significantly exceeding CP alone. Mechanistically, CP-induced membrane damage and dysregulated iron homeostasis jointly contributed to intracellular Fe²⁺ accumulation, which promoted Fenton reactions, leading to excessive reactive oxygen species production, lipid peroxidation, redox imbalance, and metabolic disruption. These processes collectively drove ferroptosis-like cell death, as confirmed by rescue experiments using ferroptosis-related inhibitors. Proteomic analysis further revealed pronounced alterations in iron homeostasis, lipid metabolism, glycolysis, DNA repair, and ribosome biosynthesis pathways. Overall, FeSO 4 redirected CP-induced oxidative stress toward ferroptosis-like death, effectively eliminating sublethally injured L. monocytogenes and preventing recovery, providing a mechanistic framework for improving CP-based food decontamination.