Maltose effective improving production and regulatory biosynthesis of plantaricin EF in Lactobacillus plantarum 163

Plantaricin EF, a kind of natural antibacterial substance, has shown inhibitory effect on most pathogen and spoilage microorganisms, which possessed great potential in food preservation. However, the lower production of plantaricin EF has limited its large-scale production and application. In this study, the effect of maltose on plantaricin EF production and its regulation mechanism in Lactobacillus plantarum 163 were investigated. Maltose significantly improved the biomass and plantaricin EF production, which increased by 3.35 and 3.99 times comparing to the control without maltose, respectively. The maximum production of plantaricin E and F in fed-batch fermentation were 10.55 mg/L and 22.94 mg/L, respectively. Besides, qPCR results showed that maltose remarkably improved transcription of plnA, plnB, plnD, plnE, plnF, plnG1 and plnH, and heighten transcription of lamR, lamK, hpk6 and rrp6. These results provided an effective method to enhance plantaricin EF production and revealed a possible regulatory mechanism from transcriptome results that hpk6, rrp6, lamK and lamR were relative to plantaricin EF production. Genes, hpk6 and rrp6, promote transcription of plnG1, whereas lamK and lamR enhance transcription of plnA, plnB and plnD, which increased plantaricin EF production. Keypoints center dot Maltose was proved to be effective in promoting the biosynthesis of plantaricin EF. center dot Maltose promoted the transcription of biosynthesis and secretion genes of plantaricin EF. center dot Up-regulation of genes lamR, lamK, hpk6 and rrp6 heightened the plantaricin EF production.

Automated summary

Maltose was found to effectively enhance the biosynthesis of plantaricin EF, promoting the transcription of related genes and increasing the production of plantaricin EF. Additionally, up-regulation of genes lamR, lamK, hpk6 and rrp6 were associated with heightened plantaricin EF production, highlighting a potential regulatory mechanism.