Mechanism of action of plasma-activated water on biomacromolecules in Salmonella Enteritidis: Biological effect, computer simulation, and transcriptomics-based analysis

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most important causes of foodborne illness in the food industry. In this work, plasma-activated water (PAW) generated from the plasma jet was employed to reduce S. Enteritidis contamination. The antibacterial mechanism of PAW was revealed from biological changes, molecular docking, and transcriptomics. Results revealed that the addition of lactic acid could improve the antibacterial activity and efficiency of PAW, and confirmed the existence and antibacterial activity of free radicals (OH, 1O2, and NO) in PAW. Meanwhile, PAW treatment caused damage to characteristic functional groups of biomolecules, and led to the oxidation of lipids and degradation of DNA. Molecular docking results further suggested that the reactive species could interact with amino acid residues around key binding sites through hydrogen bonding, affecting the stability of structures. Furthermore, the transcriptomics results indicated that PAW is primarily active on bacterial proteins and to a lesser extent on membrane lipids and DNA. Overall, the action mechanism of PAW on biomacromolecules is comprehensively analyzed in this work, and it provides a theoretical basis for the broad application of plasma technology.