Preparation of self-assembling Litsea cubeba essential oil/ diphenylalanine peptide micro/nanotubes with enhanced antibacterial properties against Staphylococcus aureus biofilm

The contamination of foodborne pathogens biofilms presents a serious challenge for global food safety, attributed to their rapid diffusion and high antimicrobial resistance. Herein, we demonstrated that Litsea cubeba essential oil (LC-EO) has sufficient antibacterial activity to eradicate S. aureus biofilm. After 4 h treatment of 2 mg/mL LC-EO, the bacterial density inside the biofilm decreased 75.89%. The study on antibiofilm mechanism indicated that during LC-EO treatment, the adhesion of S. aureus was weakened, and the transcription level of ica operon genes (biofilm formation-related) suffered varying degrees of inhibition. In addition, for improving the stability and antibiofilm activity of LC-EO, a LC-EO-loaded peptide micro/nanotubes structure (LC-EO/FNTs) was further prepared in this study via combination with diphenylalanine self-assembly technology. Compared with LC-EO treatment alone, the prepared LC-EO/FNTs showed better eradication effect on S. aureus biofilm with enhanced penetrability across the dense extracellular polymers matrix. Finally, a stable antibacterial effect of LCEO/FNTs was also obtained with application on different handmade soybean products. This study provides evidence of an innovative strategy for antibiofilm applications of natural antibacterial agents and materials in food matrix.