Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou, 310058, People's Republic of China.
College of Food Science and Technology, Henan University of Technology, Zhengzhou, 450000, People's Republic of China.
Appl Microbiol Biotechnol. 2020 Jun;104(11):5053-5064. doi: 10.1007/s00253-020-10561-8. Epub 2020 Apr 4.
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.
甘露糖赤藓糖醇脂质（MELs）是一种新型生物表面活性剂，具有优异的物理化学性质和生物活性。本研究旨在探索甘露糖赤藓糖醇脂质对食源性病原体金黄色葡萄球菌的抗菌和抗生物膜活性。生长曲线和存活率的结果表明 MELs 对金黄色葡萄球菌具有显著的抑制作用。扫描电子显微镜和透射电子显微镜的可视化图片显示了 MEL 处理细胞的明显形态和超微结构变化。此外，流式细胞术证实 MELs 可促进细胞凋亡并破坏细胞膜。值得注意的是，MEL-A 对聚苯乙烯、玻璃和不锈钢等不同材料表面的金黄色葡萄球菌生物膜也表现出出色的抗生物膜活性，这一点通过共聚焦激光扫描显微镜得到了验证。这些发现表明，MELs 的抗菌活性与抑制浮游细胞和金黄色葡萄球菌生物膜有关，表明它有可能替代应用于食品加工的抗菌剂和防腐剂。
