Zinc Ion-Coordinated Cyclic Lipopeptides: Potentiators of Antibiofilm Efficacy and Pepper Preservation

This research harnessed zinc ion coordination to enhance cyclic lipopeptides (CL), addressing limitations in antibacterial spectrum and antibiofilm efficacy. The novel zinc ion-CL complex (ZC) featured reduced particle size and elevated hydrophobicity, which augments its adherence to bacterial membranes. ZC demonstrated superior antibacterial activity against Staphylococcus aureus and Escherichia coli, with minimum inhibitory concentrations of 0.31 and 0.63 mg/mL, respectively. It also potently inhibited biofilm formation and bacterial swarming motility, both on solid surface and in aqueous environments. Mechanistic insights revealed that ZC diminished bacterial surface hydrophobicity and interferes with the synthesis of extracellular polymeric substance. Applied to chili peppers, ZC provided effective protection against pathogen contamination and maintained produce quality, highlighting its potential as a green antimicrobial agent for extending the shelf life and ensuring the safety of fresh produce.