Smart Bio-Packaging Powered by Bacteriocins

Introduction:
Bacteriocins are ribosomally synthesized peptides with selective antimicrobial activity, produced by various bacteria and archaea. Due to their specificity, low cytotoxicity, and ability to inhibit pathogens without disturbing beneficial microflora, they are considered promising natural alternatives to conventional antibiotics and chemical preservatives. Their potential application in food packaging aligns with current trends promoting clean-label, sustainable, and biodegradable solutions.

Methods:
In this study, biodegradable polymer-based films and hydrogels were developed using polycaprolactone (PCL) and sodium alginate, enriched with two model bacteriocins: nisin and pimaricin. Antibacterial properties were evaluated against three reference strains: Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Antifungal efficacy was assessed using a mixed culture of four common fungal strains. Additional assays included spectrophotometric quantification of bacterial biofilm formation, Ames test for mutagenicity, and soil biodegradation analysis over 28 days.

Results:
All bacteriocin-enriched materials demonstrated strong antimicrobial activity. Nisin showed pronounced antibacterial effects with clear inhibition zones >1 mm. Pimaricin exhibited notable antifungal action, especially against A. niger and C. globosum. Both compounds significantly reduced biofilm formation on material surfaces. No mutagenic effects were detected, and the materials, particularly alginate-based hydrogels, showed high biodegradability.

Conclusions:

The material exhibits antimicrobial properties due to the controlled release of the active substance to the food surface. PCL, as a hydrophobic polymer, ensures the relative stability of the material in an aqueous environment, allowing for the gradual and prolonged action of bacteriocin, especially against Gram-positive bacteria. The material can be used for packaging perishable products such as meat, fish, cheese or ready-made chilled meals.