Mannosylerythritol lipids (MELs) are novel biosurfactants performing excellent physical-chemical properties as well as bioactivities. This study is aimed to explore the antibacterial and antibiofilm activity of mannosylerythritol lipids against foodborne gram-positive Staphylococcus aureus. The results of growth curve and survival rate revealed the significant inhibitory effect of MELs against S. aureus. The visualized pictures by scanning electron microscope and transmission electron microscope exposed apparent morphological and ultrastructure changes of MEL-treated cells. Furthermore, flow cytometry confirmed that MELs have promoted cell apoptosis and damaged the cell membrane. Notably, MEL-A also exhibited outstanding antibiofilm activity against S. aureus biofilm on different material surfaces including polystyrene, glass, and stainless steel, verified by confocal laser scanning microscope. These findings suggest that the antimicrobial activity of MELs is related to inhibit planktonic cells and biofilm of S. aureus, indicating that it has potential to be an alternative to antibacterial agents and preservatives applied into food processing.Key Points • MELs have strong antibacterial activity against Staphylococcus aureus.• MELs mainly damage the cell membrane of Staphylococcus aureus.• Mannosylerythritol lipids inhibit the bacterial adhesion to remove biofilm.

中文翻译：

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甘露糖基赤藓糖醇脂质：通过膜介导的细胞凋亡和生物膜破坏对金黄色葡萄球菌的双重抑制模式。

甘露糖基赤藓糖醇脂质（MELs）是新型生物表面活性剂，具有出色的物理化学性质和生物活性。这项研究旨在探讨甘露糖基赤藓糖醇脂质对食源性革兰氏阳性金黄色葡萄球菌的抗菌和生物膜活性。生长曲线和存活率的结果表明MELs对金黄色葡萄球菌具有明显的抑制作用。通过扫描电子显微镜和透射电子显微镜的可视化图像暴露了MEL处理的细胞的明显的形态和超微结构变化。此外，流式细胞术证实MELs促进了细胞凋亡并破坏了细胞膜。值得注意的是，MEL-A还对包括聚苯乙烯，玻璃和不锈钢在内的不同材料表面上的金黄色葡萄球菌生物膜表现出出色的抗生物膜活性，经共聚焦激光扫描显微镜验证。这些发现表明，MEL的抗菌活性与抑制金黄色葡萄球菌的浮游细胞和生物膜有关，表明它有可能成为食品加工中使用的抗菌剂和防腐剂的替代品。要点•MEL对细菌具有很强的抗菌活性。金黄色葡萄球菌。•MELs主要破坏金黄色葡萄球菌的细胞膜。•甘露糖基赤藓糖醇脂质抑制细菌粘附以去除生物膜。