苯乳酸对单增李斯特菌的细胞膜完整性和通透性的影响

黄云坡; 孙晶; 梅红霞; 刘建春

doi:10.13386/j.issn1002-0306.2019.05.022

苯乳酸对单增李斯特菌的细胞膜完整性和通透性的影响

Effect of D- (+) -3-Phenyllactic Acid against Listeria monocytogenes 10403s on Cell Membrane Integrity and Permeability

摘要

摘要: 苯乳酸(D-(+)-3-Phenyllactic acid,PLA)是近年来在多种发酵食品中发现的天然高效抑菌小分子。本文采用流式细胞术、荧光显微镜、扫描电子显微镜等方法,研究了苯乳酸对食源性致病菌单增李斯特菌(L. monocytogenes 10403s)细胞膜通透性和完整性的影响。结果表明,苯乳酸最小抑菌浓度(Minimum inhibitory concentration,MIC)作用于该菌1 h后,细胞的通透率达到最高。通过流式细胞仪观察发现,通透细胞数占细胞总数的90.6%,且细胞膜的完整性随着作用时间的延长破坏程度越明显,且在作用1 h后,达到91.9%的破坏率。荧光显微镜直观地展现了细胞的损伤比例。在苯乳酸与L.monocytogenes 10403s作用1、3和6 h后,扫描电镜观察细胞形态有不同程度的皱缩、变形、细胞表面出现一定的孔洞,作用6 h后的细菌出现断裂、抱团和粘连现象。苯乳酸能够影响L.monocytogenes 10403s的细胞膜的通透性和完整性,为其在食品保鲜领域良好的应用提供一定的理论基础。

Abstract: D-(+) -3-Phenyllactic acid (PLA) was a novel organic acid with strong antibacterial and antifungal activities isolated from fermented food recently. In order to study the effect of PLA against L. monocytogenes 10403s on cell membrane integrity and permeability, flow cytometry, fluorescence microscopy and scanning electron microscopy were used. The results indicated that, the membrane permeation was the highest which accounted for 90.6% with flow cytometry after L. monocytogenes 10403s against with PLA (MIC) for 1 h. In addition, the integrity of cell membrane was significantly damaged with the extension of time, and the damage rate reached 91.9% after treated with PLA for 1 h. The cell membrane destruction ratios were showed by fluorescence microscopy intuitively. The microstructure of L.monocytogenes 10403s treated with PLA for 1, 3, 6 h had been determined by scanning electron microscope (SEM). The results showed that the cell wall was damaged with holes, deformation, adhesion and discoursing in group after for 6 h. PLA could affect the integrity and permeability of L.monocytogenes 10403s cell membrane, providing a theoretical basis for its good application in the field of food preservation.