Screeging of High-yield Plantaricin Producing Stains Induced by Mutations and the Fresh-keeping Effect of Plantaricin on the Preservation of Meatballs

In order to obtain a high-yield bacteriocin producing strain,Lactobacillus plantarum JL-A65 was used as the starting stain and mutagenized with atmospheric and room temperature plasma(ARTP),methylnitro nitroguanidine(MNNG),then genome shuffling was applied to the mutants. In order to study the effect of bacteriocin on meatballs,bacteriocin and sodium diacetate were added to the meatball. The results showed that the optimal irradiation time of ARTP was 40 s,two mutants named A7-10 and A8-110 were obtained and their bacteriocin production by the mutants increased by 45.1% and 48.9% respectively compared with the starting strain. The optimum concentration of MNNG was 1.5 mg/mL,two mutant strains named M2-58 and M7-111 were obtained and their bacteriocin production by the mutants increased by 46.6% and 31.3% respectively compared with the starting strain. After four rounds of genome shuffling,a strain named F4-23 was obtained and the yield of it was 413 mg/L,which increased 103.48% compared with the starting stain. There was a synergistic effect between bacteriocin and sodium diacetate. Meat products using them as additives could extend shelf life by 5 days compared with control. Research showed that physical and chemical mutagenesis combined with genome shuffling was an effective method for obtaining high-yield bacteriocin producing strain. Meatballs using bacteriocin and sodium diacetate as additives could extend its shelf life by 5 days compared with control. Bacteriocin had a good antiseptic effect on fresh-keeping.