Bioengineering of aLactococcus lactissubsp.lactisstrain enhances nisin production and bioactivity

AbstractLactococcus lactissubsp.lactisis a food bacterium that has been utilized for decades in food fermentation and the development of high-value industrial goods. Among these, nisin is produced by several strains ofL. lactissubsp.lactisplays a crucial role as a food bio-preservative. The relative expression of the gene cluster involved in nisin production was evaluated using qPCR analysis. Additionally, a series of re-transformations of the strain introducing multi copies of thenisAandnisRKgenes involved in nisin biosynthesis were developed. The simultaneous expression ofnisAandnisZgenes was used to potentiate the effective inhibition of foodborne pathogens. Further, qPCR analysis revealed a low expression of thenisAandnisRKgenes in wild-typeL. lactissubsp.lactis. After several re-transformations of the strain with thenisAandnisRKgenes, a high expression of these genes was obtained, contributing to improved nisin production. Also, the co-expression ofnisAandnisZgenes results in highly efficient antimicrobial activity. Hence, this study would supply an approach to enhancing nisin production during industrial processes and antimicrobial activity.