TMT-Based Quantitative Proteomics Analyses Reveal the Antibacterial Mechanisms of Anthocyanins from Aronia melanocarpa against Escherichia coli O157:H7.

Aronia melanocarpa anthocyanins (AMAs), as natural plant extracts, can control pathogens and are attracting increasing attention. In this study, a tandem mass tag (TMT) quantitative proteomics method combined with multiple reaction monitoring (MRM) was used to explore the antibacterial mechanism of AMAs against Escherichia coli at the protein level. The results showed that 1739 proteins were identified in E. coli treated with AMAs, of which 628 were altered, including 262 downregulated proteins and 366 upregulated proteins. Bioinformatics analysis showed that these differentially expressed proteins have different molecular functions and participate in different molecular pathways. AMAs can affect E. coli protein biosynthesis, DNA replication and repair, oxidative stress response, peptidoglycan biosynthesis, and homeostasis. These pathways induce morphological changes and cell death. The results of this study help understand the molecular mechanism of the inhibitory effect of AMAs on food-borne pathogens and provide a reference for further development of plant-derived antimicrobial agents.