A Novel Bioactive Antimicrobial Film Based on Polyvinyl Alcohol-Protocatechuic Acid: Mechanism and Characterization of Biofilm Inhibition and its Application in Pork Preservation

Biofilms in food processing environments pose a potential risk of contamination by pathogenic and spoilage microorganisms, and Yersinia enterocolitica, known for its wide temperature adaptation, is the third most common zoonotic pathogen in the European Union. This study investigates the inhibitory effects of protocatechuic acid (PCA) at sub-inhibitory concentrations on various stages of Y. enterocolitica biofilm formation. Core genes are identified through transcriptome data and weighted gene co-expression network analysis (WGCNA), and the potential binding sites are predicted using molecular docking. Additionally, polyvinyl alcohol (PVA) films containing PCA are prepared to assess their antibacterial and mechanical properties. PCA is found to inhibit biofilm formation by up to 50.5% without affecting bacterial growth, reducing flagella-mediated motility, hydrophobicity, cohesion, and extracellular polysaccharides (EPS) content, and inhibiting the production of acyl-homoserine lactones (AHLs). Transcriptome data reveal that PCA inhibits biofilm formation by suppressing the quorum sensing system and reducing the expression of genes such as CsrD, yenR, FlhD, and FlhC. The PVA-PCA antimicrobial film exhibits robust mechanical properties, effectively reducing total colonies in pork and slowing down the deterioration rate. This study enhances our understanding of PCA’s inhibitory effects on Y. enterocolitica and suggests its potential application as a quorum-sensing inhibitor in antimicrobial films for the food industry.