食品科学 ›› 2020, Vol. 41 ›› Issue (23): 70-76.doi: 10.7506/spkx1002-6630-20191106-071

• 基础研究 • 上一篇    下一篇

苯乳酸和醋酸联用对单核细胞增生李斯特菌的协同抑菌机理

宁亚维,付浴男,何建卓,苏丹,侯琳琳,王志新,贾英民   

  1. (1.河北科技大学生物科学与工程学院,河北 石家庄 050018;2.北京工商大学食品与健康学院,北京 100048)
  • 出版日期:2020-12-15 发布日期:2020-12-28
  • 基金资助:
    河北省杰出青年科学基金项目(C2016208142);河北省青年拔尖人才项目

Synergistic Antibacterial Mechanism of Phenyllactic Acid Combined with Acetic Acid against Listeria monocytogenes

NING Yawei, FU Yunan, HE Jianzhuo, SU Dan, HOU Linlin, WANG Zhixin, JIA Yingmin   

  1. (1. School of Biological Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; 2. School of Food and Health, Beijing Technology and Business University, Beijing 100048, China)
  • Online:2020-12-15 Published:2020-12-28

摘要: 目的:研究苯乳酸和醋酸联用对单核细胞增生李斯特菌的协同抑菌活性及对细胞膜、DNA损伤的机理。方法:通过二倍稀释法考察苯乳酸和醋酸对单核细胞增生李斯特菌的最小抑菌浓度(minimum inhibitory concentration,MIC)和部分抑菌浓度指数;采用平板菌落计数法绘制时间-杀菌曲线;从Zeta电位、膜电势、细胞膜完整性、细胞超微结构、DNA等方面考察苯乳酸和醋酸对单核细胞增生李斯特菌的抑菌机制。结果:苯乳酸和醋酸对单核细胞增生李斯特菌的MIC分别为2.25、1.75 mg/mL,苯乳酸与醋酸组合的部分抑菌浓度指数为0.5,表明苯乳酸与醋酸对单核细胞增生李斯特菌的抑制具有协同效应;Zeta电位结果显示苯乳酸与醋酸有效改变了细胞表面电荷;通过DiSC3(5)荧光探针标记考察膜电势的变化,表明苯乳酸与醋酸能消散膜电势;流式细胞仪和荧光显微镜分析得出苯乳酸与醋酸破坏细胞膜完整性;经MIC苯乳酸、MIC醋酸及1/4 MIC苯乳酸+1/2 MIC醋酸作用后,单核细胞增生李斯特菌菌体变形、出现黏连、内容物泄出;琼脂糖凝胶电泳结果表明苯乳酸和醋酸可损伤DNA。结论:苯乳酸和醋酸联用可使细胞表面电荷减少,细胞膜电势消散,破坏细胞膜完整性,从而进入细胞与DNA发生相互作用使细胞死亡,进而发挥协同抑菌作用。本研究为苯乳酸用于食品保鲜防腐提供了理论参考。

关键词: 苯乳酸;醋酸;抑菌机制;细胞膜;DNA

Abstract: Objective: To investigate the synergistic antibacterial activity and mechanism of phenyllactic acid (PLA) combined with acetic acid (ACE) against L. monocytogenes. Methods: The double broth dilution method was used to measure the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index. The time-killing curve was constructed by plate counting method. The antibacterial mechanism was studied by measuring Zeta potential, membrane depolarization, membrane integrity, cell morphology and DNA damage. Results: The MICs of PLA and ACE were 2.25 and 1.75 mg/mL, respectively, and the fractional inhibitory concentration index of PLA in combination with ACE was 0.5, suggesting that combination of PLA (1/4 MIC) and ACE (1/2 MIC) can exert a synergistic effect against L. monocytogenes. Zeta potential results showed that PLA and/or ACE effectively changed the cell surface charge. DiSC3(5) fluorescent probe labeling results indicated that PLA and ACE could dissipate membrane potential. Flow cytometry and fluorescence microscopy analysis showed that PLA, ACE and their combination could disrupt cell membrane integrity. After treatment with PLA at MIC, ACE at MIC or PLA (1/4 MIC) plus ACE (1/2 MIC), L. monocytogenes cells became deformed and adhered together, and the contents leaked out. Gel electrophoresis images showed that PLA and ACE could damage DNA. Conclusion: Combination of PLA and ACE shows a synergistic antibacterial activity by reducing cell surface charge, causing membrane depolarization, destroying the integrity of the cell membrane and consequently entering into the cells to interact with DNA, and finally lead to cell death. This investigation can provide a theoretical basis for applying PLA in food preservation.

Key words: phenyllactic acid; acetic acid; antibacterial mechanism; cell membrane; DNA

中图分类号: