摘要
Bacteriocins exhibit excellent antimicrobial activity and can inhibit Listeria monocytogenes,a common foodborne pathogen in food matrices,thus holding promising application prospects in the food industry.However,low yield of biosynthesis remains the bottleneck restricting the widespread application of bacteriocins.In this study,PLA2,a bacteriocin derived from Lactiplantibacillus plantarum was successfully expressed in Bacillus subtilis WB800.In vitro antimicrobial activity assays demonstrated that PLA2 exerted significant inhibitory effects against L.monocytogenes.PLA2 retained antimicrobial activity within a pH range of 2-6 and showed outstanding thermostability,with almost no loss of antibacterial activity after treatment at 121℃ for 30 min,and is sensitive to pepsin and trypsin.The antibacterial activity of PLA2 in B.subtilis was significantly improved via promoter screening,optimization of induction conditions,spacer sequence modification and chassis strain engineering.When the supernatant of PLA2 cell lysate was co-cultured with L.monocytogenes,the survival rate of the path-ogen was reduced by 333-fold,representing an 8.9×10^(4)-fold decrease compared with the untreated control group.In comparison with nisin(a bacteriocin produced by Lactococcus lactis),the antimicrobial efficacy of PLA2 cell lysate supernatant against L.monocytogenes was equivalent to that of 2.66 g/L nisin solution of the same volume.This study provides an effective strategy for the biosynthesis of bacteriocins,which has important application value in the field of food safety.
基金
supported by the National Key Research and Development Program of China(2022YFD2101402)
the National Natural Science Foundation of China(22208125)
the Key Core Technology Research Project in Taiyuan City(2024TYJB0146)
the Joint Funding Program for Science,Technology,and Innovation in the Resource Chemistry Industry(N2022Z003).
