TMT-based quantitative proteomics and non-targeted metabolomic analyses reveal the inactivation mechanism of cold atmospheric plasma against Pseudomonas aeruginosa

Abstract

Cold atmospheric plasma (CAP) has emerged as a potent nonthermal inactivation strategy in food processing over the past two decades. However, the underlying mechanisms of inactivation remain unclear. In this study, Tandem Mass Tag (TMT)-based quantitative proteomics and non-targeted metabolomic analyses were conducted to investigate the responses of Pseudomonas aeruginosa to CAP. The results revealed significant alterations in 170 differentially expressed proteins (DEPs) and 490 differential metabolites (DMs) upon air-CAP treatment. P. aeruginosa demonstrated a regulatory response at the transcription and translation levels, upregulating proteins to resist external stimuli. Conversely, a predominant down-regulation of proteins indicated that CAP treatment profoundly disrupted the cell structure, inhibiting movement, colonization ability, virulence protein secretion, and bacterial biofilm formation. Moreover, CAP compromised the bacterium's ability to acquire energy, thereby disrupting its defense mechanisms, reducing drug resistance, and potentially leading to bacterial death. This comprehensive study enhances our understanding of the mode of action of air-CAP against P. aeruginosa. The findings provide a robust experimental foundation for considering CAP as an effective inactivation method in the food industry.