Zhao Deyin, Meng Fanqiang, Zhou Libang, Lu Fengxia, Bie Xiaomei, Sun Jing, Lu Zhaoxin, Lu Yingjian
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China.
College of Food Science & Engineering, Nanjing University of Finance and Economics, Nanjing, China.
Appl Microbiol Biotechnol. 2021 Apr;105(7):2713-2723. doi: 10.1007/s00253-021-11218-w. Epub 2021 Mar 12.
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: • Maltose was proved to be effective in promoting the biosynthesis of plantaricin EF. • Maltose promoted the transcription of biosynthesis and secretion genes of plantaricin EF. • Up-regulation of genes lamR, lamK, hpk6 and rrp6 heightened the plantaricin EF production.
植物乳杆菌素EF是一种天然抗菌物质，已显示出对大多数病原微生物和腐败微生物具有抑制作用，在食品保鲜方面具有巨大潜力。然而，植物乳杆菌素EF的低产量限制了其大规模生产和应用。本研究调查了麦芽糖对植物乳杆菌163中植物乳杆菌素EF产量的影响及其调控机制。麦芽糖显著提高了生物量和植物乳杆菌素EF产量，与无麦芽糖的对照组相比，分别增加了3.35倍和3.99倍。分批补料发酵中植物乳杆菌素E和F的最高产量分别为10.55mg/L和22.94mg/L。此外，qPCR结果表明，麦芽糖显著提高了plnA、pln B、plnD、plnE、plnF、plnG1和plnH的转录水平，并提高了lamR、lamK、hpk6和rrp6的转录水平。这些结果提供了一种提高植物乳杆菌素EF产量的有效方法，并从转录组结果中揭示了一种可能的调控机制，即hpk6、rrp6、lamK和lamR与植物乳杆菌素EF产量相关。基因hpk6和rrp6促进plnG1的转录，而lamK和lamR增强plnA、pln B和plnD的转录，从而增加了植物乳杆菌素EF的产量。要点：• 麦芽糖被证明对促进植物乳杆菌素EF的生物合成有效。• 麦芽糖促进了植物乳杆菌素EF生物合成和分泌基因的转录。• 基因lamR、lamK、hpk6和rrp6的上调提高了植物乳杆菌素EF的产量。
