Sorrentino Elena, Tremonte Patrizio, Succi Mariantonietta, Iorizzo Massimo, Pannella Gianfranco, Lombardi Silvia Jane, Sturchio Marina, Coppola Raffaele
Department of Agricultural Environmental and Food Sciences, University of Molise, Campobasso, Italy.
Front Microbiol. 2018 Jun 26;9:1373. doi: 10.3389/fmicb.2018.01373. eCollection 2018.
The 3-Phenyllactic acid (PLA) produced by various lactic acid bacteria (LAB) possesses a broad spectrum of antimicrobial activity. In this study, the effect of PLA against was studied with the aim to obtain additional information about its mechanism of action. The effect of pH on the antilisterial activity of PLA was investigated and a pH-dependent behavior, typical of weak acid, was detected. The antilisterial effect of PLA was firstly compared to that produced by lactic acid (LA) and than to that expressed by phenolic acids (gallic, caffeic, and ferulic acids) evaluating minimum inhibitory concentration (MIC), MBC, and survival kinetic parameters. PLA showed MIC values and death kinetic parameters significantly different from those exhibited by LA and by tested phenolic acids. In particular, the MIC value observed for PLA resulted lower than that of the other preservative compounds studied herein, and consistent with the quantity generally produced by LAB. Moreover, the effect of PLA and phenolic acids on bacterial surface charge and loss of cellular content resulted different. The overall results highlighted strong differences in the antilisterial mechanism of action among PLA and other compounds such as LA and phenols. Specifically, it is possible to hypothesize that the antilisterial mechanism of action due to PLA is associated with the affinity to cell surface, which contributes to the cellular damage.
多种乳酸菌（LAB）产生的3-苯乳酸（PLA）具有广谱抗菌活性。在本研究中，对PLA对[具体对象未提及]的作用进行了研究，旨在获取有关其作用机制的更多信息。研究了pH对PLA抗李斯特菌活性的影响，并检测到了典型的弱酸pH依赖性行为。首先将PLA的抗李斯特菌作用与乳酸（LA）产生的作用进行比较，然后与酚酸（没食子酸、咖啡酸和阿魏酸）表现出的作用进行比较，评估最小抑菌浓度（MIC）、MBC和存活动力学参数。PLA显示出的MIC值和死亡动力学参数与LA和测试酚酸所显示的有显著差异。特别是，观察到的PLA的MIC值低于本文研究的其他防腐剂化合物的MIC值，并且与LAB通常产生的量一致。此外，PLA和酚酸对细菌表面电荷和细胞内容物损失的影响有所不同。总体结果突出了PLA与其他化合物（如LA和酚类）在抗李斯特菌作用机制上的强烈差异。具体而言，可以推测PLA的抗李斯特菌作用机制与对细胞表面的亲和力有关，这会导致细胞损伤。
