环肽、3-苯乳酸与苯丙酸组合物对双菌生物被膜的影响

为研究植物乳杆菌CCFM8724产生的3种代谢物环亮氨酸脯氨酸二肽、3-苯乳酸、苯丙酸对变异链球菌和白色念珠菌双菌生物被膜的作用及其作用机制，测定了3种代谢物的组合物对变异链球菌和白色念珠菌双菌生物被膜量、胞外多糖和胞外蛋白产量、群体感应信号分子AI-2产量及生物被膜结构的影响，并通过分子对接的方式探究小分子代谢物结合致病菌靶点的方式和构象。结果表明：组合物的干预使变异链球菌和白色念珠菌双菌生物被膜量减少了79.4%,水不溶性胞外多糖和胞外蛋白的产量分别减少了63.8%、60.2%,群体感应信号分子AI-2产量减少了80.7%,同时破坏了生物被膜结构。分子对接结果显示：组合物可以与变异链球菌PtxA蛋白和白色念珠菌Fba蛋白的靶点结合，影响其糖代谢，进而抑制二者形成生物被膜。通过探究植物乳杆菌CCFM8724抑制双菌生物被膜潜在的物质基础，旨在从分子水平揭示组合物环亮氨酸脯氨酸二肽、3-苯乳酸、苯丙酸可能的抑菌机理，为植物乳杆菌CCFM8724及其代谢物组合物开发口腔益生菌和后生元产品提供一定的理论依据。

Effect of Cyclic Peptide, 3-Phenyllactic Acid and Hydrocinnamic Acid Composition on Dual-Species Biofilm

To explore the effects of three metabolites mixture [cyclo (leucine-proline) dipeptide, 3-phenyllactic acid and hydrocinnamic acid] produced by Lactiplantibacillus plantarum CCFM8724 on the biofilm of Streptococcus mutans and Candida albicans, and their mechanisms, dual-species biofilm formation, the production of extracellular polysaccharides and extracellular proteins, the production of quorum sensing signal molecule AI-2, and the biofilm structure were determined. The way and conformation of small moleculae metabolites binding to pathogenic targets was explored by molecular docking. The results showed that the composition significantly reduced the biofilm formation of S.mutans and C.albicans (reduction rate 79.4%), the production of water-insoluble exopolysaccharides (reduction rate 63.8%), extracellular protein (reduction rate 60.2%), and the production of quorum sensing signal molecule AI-2 (reduction rate 80.7%), and destroyed the biofilm structure at the same time. Molecular docking results revealed that the three metabolites could bind to targets such as S. mutans PtxA protein and C. albicans Fba protein, affect their sugar metabolism, and consequently inhibit biofilm formation. Through exploring the potential material basis of L. plantarum CCFM8724 to inhibit dual-species biofilm, the aim was to reveal the possible antibacterial mechanism of the composition consisting of cyclo (leucine-proline) dipeptide, 3-phenyllactic acid and hydrocinnamic acid at molecular level, and provide a theoretical basis for the development of L. plantarum CCFM8724 and its composition into oral probiotic and postbiotic products.