Niu Ben, Sun Yiming, Niu Yongwu, Qiao Shan
National Engineering Research Center for Wheat & Corn Further Processing, Zhengzhou 450001, China.
College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China.
Microorganisms. 2024 Dec 2;12(12):2478. doi: 10.3390/microorganisms12122478.
Biofilm formation by is a major cause of secondary food contamination, leading to significant economic losses. While rhamnolipids (RLs) have shown effectiveness against , their ability to remove biofilms is limited when used alone. Ultrasound (US) is a non-thermal sterilization technique that has been found to enhance the delivery of antimicrobial agents, but it is not highly effective on its own. In this study, we explored the synergistic effects of combining RLs with US for biofilm removal. The minimum biofilm inhibitory concentration (MBIC) of RLs was determined to be 32.0 mg/L. Using a concentration of 256.0 mg/L, RLs alone achieved a biofilm removal rate of 63.18%. However, when 32.0 mg/L RLs were combined with 20 min of US treatment, the removal rate increased to 62.54%. The highest biofilm removal rate of 78.67% was observed with 256.0 mg/L RLs and 60 min of US exposure. Scanning electron microscopy analysis showed that this combined treatment significantly disrupted the biofilm structure, causing bacterial deformation and the removal of extracellular polymeric substances. This synergistic approach not only inhibited bacterial metabolic activity, aggregation, and adhesion but also reduced early biofilm formation and decreased levels of extracellular polysaccharides and proteins. Furthermore, US treatment improved biofilm permeability, allowing better penetration of RLs and interaction with bacterial DNA, ultimately inhibiting DNA synthesis and secretion. The combination of RLs and US demonstrated superior biofilm removal efficacy, reduced the necessary concentration of RLs, and offers a promising strategy for controlling biofilm formation in the food industry.
[细菌名称]形成生物膜是导致食品二次污染的主要原因，会造成重大经济损失。虽然鼠李糖脂（RLs）已显示出对[细菌名称]的有效性，但单独使用时其去除生物膜的能力有限。超声（US）是一种非热杀菌技术，已发现它能增强抗菌剂的递送效果，但自身效果并不理想。在本研究中，我们探讨了将鼠李糖脂与超声联合用于去除生物膜的协同效应。鼠李糖脂的最低生物膜抑制浓度（MBIC）确定为32.0 mg/L。使用256.0 mg/L的浓度时，单独的鼠李糖脂实现了63.18%的生物膜去除率。然而，当32.0 mg/L的鼠李糖脂与20分钟的超声处理相结合时，去除率提高到了62.54%。在256.0 mg/L的鼠李糖脂和60分钟的超声照射下，观察到最高生物膜去除率为78.67%。扫描电子显微镜分析表明，这种联合处理显著破坏了生物膜结构，导致细菌变形并去除了细胞外聚合物。这种协同方法不仅抑制了细菌的代谢活性、聚集和粘附，还减少了早期生物膜的形成，并降低了细胞外多糖和蛋白质的水平。此外，超声处理提高了生物膜的渗透性，使鼠李糖脂能更好地渗透并与细菌DNA相互作用，最终抑制DNA合成和分泌。鼠李糖脂与超声的联合显示出卓越的生物膜去除效果，降低了鼠李糖脂的必要浓度，并为控制食品工业中的生物膜形成提供了一种有前景的策略。
