Breeding of a High-Nisin-Yielding Bacterial Strain and Multiomics Analysis

Nisin is a green, safe and natural food preservative. With the expansion of nisin application, demand for has gradually increased, which equates to increased requirements production. In this study, Lactococcus lactis subsp. lxl was used as original strain, compound mutation method applied induce mutations. A high-yielding genetically stable strain (Lactobacillus A32) identified, with titre raised by 332.2% up 5089.29 IU/mL. Genome transcriptome sequencing analyse A32 compare it strain. The comparative genomics results show that 107 genes in genome had mutations most base were not located four well-researched nisin-related operons, nisABTCIPRK, nisI, nisRK nisFEG: 39 single-nucleotide polymorphisms (SNPs), 34 insertion deletion transcription expression 92 changed significantly, 27 these differentially expressed upregulated, while 65 downregulated. Our findings suggest output L. A32, accompanied changes DNA replication-related gene dnaG, ABC-ATPase transport-related patM tcyC, cysteine thiometabolism-related cysS, purine metabolism-related purL. study provides new insights into traditional genetic mechanisms involved production lactis, could provide clues more efficient metabolic engineering process.