Bacteriocin Mining in PCZ4 with Broad-Spectrum Antibacterial Activity and Its Biopreservative Effects on Snakehead Fish.

Some lactic acid bacteria (LAB) produce antibacterial substances such as bacteriocins, making them promising candidates for food preservation. In our study, PCZ4-a strain with broad-spectrum antibacterial activity-was isolated from traditional fermented kimchi in Sichuan. Whole-genome sequencing of PCZ4 revealed one chromosome and three plasmids. Through BAGEL4 mining, classes IIa and IIb bacteriocin plantaricin S were identified. Additionally, two new antibacterial peptides, Bac1109 and Bac2485, were predicted from scratch by limiting open reading frames. Furthermore, during refrigerated storage of snakehead fish, PCZ4 crude extract reduced the total bacterial count, slowed the increase in TVB-N and pH values, improved the sensory quality of the snakehead, and extended its shelf life by 2 days. Meanwhile, PCZ4 effectively inhibited the growth of artificially contaminated in snakehead fish. These findings indicate that PCZ4 can produce multiple antibacterial substances with strong potential for food preservation applications.