Abstract e-Poly-lysine ( e -PL) is widely recognized as a natural antibacterial agent because of its broad spectrum antimicrobial property. However, the mechanism of e -PL against pathogens at the molecular level has not been yet thoroughly described. This work aimed at investigating the antibacterial activity and mechanism of e -PL at the molecular level against Listeria monocytogenes . e -PL exhibited antibacterial activities against L. monocytogenes at a low dosage of 0.1 mg/mL. After e -PL treatment, the marked change on the morphology of bacterial cells was observed by Transmission Electron Microscopy. The characterization of cell membrane surfaces through electrical conductivity, cell membrane permeability and surface zeta potential was also well documented. The intracellular materials (ATP, DNA and proteins) and intracellular enzymes (AKP, ATPase and β -Galactosidase) were analyzed, which revealed the destructive effect of e -PL on bacterial cells. SDS-PAGE investigation of bacterial proteins demonstrated that the loss of soluble proteins was obvious as well. Results of respiration metabolism manifested that e -PL inhibited the Embden-Meyerhof-Parnas pathway and the three key enzymes in this pathway. Nevertheless, the e -PL has no inhibition effects on Topo I/II. Finally, e -PL was applied to preserve cheese and showed outstanding antibiotic activity during 15-days storage period at 4 °C and 25 °C.

中文翻译：

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ε-聚赖氨酸对单核细胞增生李斯特菌的抑菌机理及其在奶酪中的应用

摘要 e-聚赖氨酸（e-PL）因其广谱抗菌特性而被广泛认为是一种天然抗菌剂。然而，e-PL在分子水平上对抗病原体的机制尚未得到彻底描述。这项工作旨在从分子水平研究 e-PL 对单核细胞增生李斯特菌的抗菌活性和机制。e-PL 在 0.1 mg/mL 的低剂量下表现出对单核细胞增生李斯特菌的抗菌活性。e-PL处理后，透射电子显微镜观察到细菌细胞形态的显着变化。通过电导率、细胞膜渗透性和表面 zeta 电位对细胞膜表面的表征也有充分的记录。细胞内物质（ATP、DNA 和蛋白质）和细胞内酶（AKP、ATPase 和 β-半乳糖苷酶）进行分析，揭示了 e-PL 对细菌细胞的破坏作用。细菌蛋白质的 SDS-PAGE 研究表明可溶性蛋白质的损失也很明显。呼吸代谢结果表明e-PL抑制Embden-Meyerhof-Parnas途径和该途径中的三个关键酶。然而，e-PL 对 Topo I/II 没有抑制作用。最后，e-PL 用于保存奶酪，并在 4°C 和 25°C 的 15 天储存期内显示出出色的抗生素活性。呼吸代谢结果表明e-PL抑制Embden-Meyerhof-Parnas途径和该途径中的三个关键酶。然而，e-PL 对 Topo I/II 没有抑制作用。最后，e-PL 用于保存奶酪，并在 4°C 和 25°C 的 15 天储存期内显示出出色的抗生素活性。呼吸代谢结果表明e-PL抑制Embden-Meyerhof-Parnas途径和该途径中的三个关键酶。然而，e-PL 对 Topo I/II 没有抑制作用。最后，e-PL 用于保存奶酪，并在 4°C 和 25°C 的 15 天储存期内显示出出色的抗生素活性。