A Novel Plantaricin 32 Effectively Inactivates Listeria monocytogenes and Prolongs the Shelf Life of Pork in Conjunction with Chitosan

Lactiplantibacillus plantarum 32 was isolated from traditional Chinese fermented long beans. Plantaricin 32, a novel bacteriocin, was purified from L. plantarum 32 fermentation broth. The molecular weight of plantaricin 32 is 956 Da, and its amino acid sequence is N-Arg-Gly-Pro-Gly-Lys-Thr-Asp-Glu-OH. Plantaricin 32 exhibits a broader antibacterial spectrum and significant stability across various pH levels and temperatures. It can disrupt the permeability and integrity of L. monocytogenes' cell membrane, resulting in the leakage of nucleic acids and proteins of L. monocytogenes cells, thereby causing cell death. Meanwhile, plantaricin 32 can interact with the genomic DNA major groove in AG-rich regions. Additionally, plantaricin 32 + 1.0% chitosan effectively inactivates L. monocytogenes in pork and improves its quality indices. These results indicate that plantaricin 32 can inactivate foodborne pathogens and offer a promising natural preservative to prolong the shelf life of meat and its related products across the agriculture, livestock, and food industries.