【作者】 宁亚维； 张东春； 付浴男； 马梦戈； 王志新； 贾英民；

【Author】 Ning Yawei;Zhang Dongchun;Fu Yunan;Ma Mengge;Wang Zhixin;Jia Yingmin;College of Food Science and Biology,Hebei University of Science and Technology;Beijing Advanced Innovation Center for Food Nutrition and Human Health,Beijing Technology and Business University;

【机构】 河北科技大学食品与生物学院； 北京工商大学北京食品营养与人类健康高精尖创新中心；

【摘要】 苯乳酸可由乳酸菌代谢产生,具有抑菌谱广与安全性高等优点,在食品防腐中具有较高应用潜力。前期发现苯乳酸与乳酸共存时抑菌活性增强。因此,以蜡样芽胞杆菌为指示菌考察苯乳酸与乳酸的联合抑菌作用及机制。首先,通过棋盘法考察了苯乳酸与乳酸的联合抑菌效应;其次,采用流式细胞术、荧光光谱等技术从细胞层面分析了抑菌靶位。最后,基于iTRAQ技术从蛋白质表达水平探明了抑菌机制。结果表明:苯乳酸与乳酸具有协同抑制效应,两者联用可协同破坏细胞壁与膜完整性,消散细胞膜电势,导致内容物泄露。蛋白质组学结合生物信息学分析显示,苯乳酸通过抑制钾离子转运、干扰核糖体功能等发挥抑菌作用;乳酸通过抑制磷转运,干扰TCA循环、核糖体功能以及嘌呤和嘧啶代谢等导致细胞死亡;苯乳酸和乳酸联用通过抑制钾离子及磷转运,并影响核糖体、嘌呤和嘧啶的合成等发挥抑菌作用。本研究可为苯乳酸在食品防腐中的应用以及拮抗乳酸菌的筛选提供科学依据。更多还原

【Abstract】 Phenyllactic acid(PLA) metabolized by lactic acid bacteria has promising application potential in food preservative due to the advantages of wide antibacterial spectrum and high safety.The antibacterial activity of PLA was enhanced when coexisted with lactic acid(LA).Therefore,the combined antibacterial effect and mechanism of PLA and LA was investigate using Bacillus cereus as indicator bacteria.Firstly,the combined antibacterial effect of PLA and LA was investigated by checkerboard method.Secondly,the antimicrobial targets were analyzed by flow cytometry and fluorescence spectroscopy.Finally,the antibacterial mechanism was elucidated from the protein expression level by iTRAQ-based proteomics analysis.The results showed that PLA and LA had synergistic inhibitory effects,and the combination of PLA and LA could synergistically destroy the integrity of cell wall and membrane,dissipate cell membrane potential,and lead to the leakage of cellular content.Proteomics combined with bioinformatics analysis showed that PLA could inhibit the potassium transport and interfere with ribosome function to exert antibacterial effects.LA could hinder the phosphorus transport,disturb the TCA cycle,ribosome function,as well as purine and pyrimidine metabolism further to cause cell death.The combination of PLA and LA can disrupt the transport of potassium ions and phosphorus,and affect the synthesis of ribosomes,purines and pyrimidines to inhibit the cells.This study can provide scientific basis for the application of PLA in food preservative and the screening of antagonistic lactic acid bacteria.更多还原