Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China.
Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055, China.
Int J Mol Sci. 2023 Jan 19;24(3):1986. doi: 10.3390/ijms24031986.
Dental plaque, a complex biofilm system established by cariogenic bacteria such as (), is the initiator of dental caries. Studies have found that the cell-free supernatant (CFS) of could inhibit biofilm formation. However, the main antibiofilm substance of the CFS that acts against is unclear. The present study found that the CFS of () ATCC 14917 had the strongest antibiofilm effect among the five tested oral . Further bioassay-guided isolation was performed to identify the main antibiofilm substance. The antibiofilm effect of the end product, named , was observed and the structure of it was elucidated by using Q-TOF MS, 2D NMR and HPLC. The results showed that several components in the CFS had an antibiofilm effect; however, the effect of was the strongest, as it could reduce the generation of exopolysaccharides and make the biofilm looser and thinner. After structure elucidation and validation, was identified as a mixture of lactic acid (LA) and valine. Additionally, LA was shown to be the main antibiofilm substance in . In summary, this study found that the antibiofilm effect of the CFS against was attributable to the comprehensive effect of multiple components, among which LA played a dominant role.
牙菌斑是一种由致龋菌（如 (））等建立的复杂生物膜系统，是龋齿的启动因子。研究发现， （）的无细胞上清液（CFS）可以抑制 生物膜的形成。然而， （）CFS 中针对 的主要抗生物膜物质尚不清楚。本研究发现，在所测试的五种口腔 （）中， （）ATCC 14917 的 CFS 具有最强的抗生物膜作用。进一步进行基于生物测定的分离以鉴定主要的抗生物膜物质。观察到末端产物（命名为 ）的抗生物膜作用，并通过 Q-TOF MS、2D NMR 和 HPLC 阐明其结构。结果表明，CFS 中的几种成分具有抗生物膜作用；然而， 的作用最强，因为它可以减少胞外多糖的产生，并使生物膜更疏松和更薄。经过结构阐明和验证， 被鉴定为乳酸（LA）和缬氨酸的混合物。此外，LA 被证明是 中的主要抗生物膜物质。总之，本研究发现， （）CFS 对 的抗生物膜作用归因于多种成分的综合作用，其中 LA 起主导作用。
