Lemon essential oil (LEO) is a common natural antibacterial substance, and encapsulating LEO into nanoemulsions (NEs) can improve their stability and broaden its application. Our study aimed to investigate the bacterial inhibitory effect of LEO-NEs against Escherichia coli (E. coli). Results showed that the minimum inhibitory concentration (MIC) of LEO-NEs was 6.25 mg/mL, and the time-kill curve showed that E. coli were significantly killed by LEO-NEs after 5 h of treatment at 1MIC. Flow-cytometry analysis showed that LEO-NEs adversely affected the cell-membrane depolarisation, cell-membrane integrity, and efflux pump function of E. coli. Confocal laser scanning microscopy demonstrated that 8MIC of LEO-NEs induced changes in the cell-membrane permeability and cell-wall integrity of E. coli. Proteomic results suggested that the mode of action LEO-NEs against E. coli was to enhance bacterial chemotaxis and significantly inhibit ribosomal assembly. They may also affect butyric acid, ascorbic acid and aldehyde metabolism, and sulphur-relay system pathways. In conclusion, LEO-NEs had potential application as a natural antibacterial agent for the control of E. coli in the food industry.

柠檬精油（LEO）是一种常见的天然抗菌物质，将LEO封装到纳米乳液（NEs）中可以提高其稳定性并拓宽其应用范围。我们的研究旨在研究 LEO-NEs 对大肠杆菌( E. coli )的细菌抑制作用。结果显示，LEO-NEs的最低抑菌浓度（MIC）为6.25 mg/mL，时效曲线显示， 1MIC处理5 h后，LEO-NEs对大肠杆菌有显着的杀灭作用。流式细胞术分析表明，LEO-NE 对大肠杆菌的细胞膜去极化、细胞膜完整性和外排泵功能产生不利影响。共聚焦激光扫描显微镜表明，8MIC 的 LEO-NE 会引起大肠杆菌细胞膜通透性和细胞壁完整性的变化。蛋白质组学结果表明，LEO-NEs 对大肠杆菌的作用方式是增强细菌趋化性并显着抑制核糖体组装。它们还可能影响丁酸、抗坏血酸和醛代谢以及硫中继系统途径。总之，LEO-NEs 具有作为天然抗菌剂用于控制食品工业中大肠杆菌的潜在应用。