Purification and Characterization of Plantaricin PQ12: A Novel Bacteriocin from Lactiplantibacillus plantarum Isolated from Fermented Cucumbers, with Inhibitory Activity against Foodborne Pathogens

High Resolution Image Download MS PowerPoint Slide Foodborne pathogens pose a significant threat to public health and the food industry, necessitating the development of effective antimicrobial strategies. Bacteriocins, with their broad-spectrum antibacterial activity, offer a promising solution, though their availability remains limited. This study aimed to identify and characterize bacteriocin-producing lactic acid bacteria (LAB) strains from fermented cucumbers. Twenty LAB strains were isolated and screened for bacteriocin production. Among these, the bacteriocin-producing strain was identified as Lactiplantibacillus plantarum . The bacteriocin was purified and characterized as a class IIb plantaricin PQ12 with a molecular weight of 12 kDa. It exhibited significant thermal stability, maintained its activity within an acidic to neutral pH range, but was inactivated by proteases. Additionally, the purified bacteriocin effectively inhibited the growth of Salmonella typhimurium in UHT milk. These findings suggest that plantaricin PQ12 could serve as a biopreservative in the food industry, providing a natural alternative to chemical preservatives.