Quorum sensing (QS) exists in bacteria to communicate with each other and regulate group behaviors in a cell density-dependent manner, which uses signal molecule autoinducer-2 (AI-2) to intra- and inter-species communication. Effects of exogenous AI-2 on biofilm formation and environmental tolerance in Lactobacillus plantarum are the focus of this review. The responses to the exogenous AI-2 cross multiple physiological metabolic behaviors involving the bacteria growth, morphological characterization, biofilm development, extracellular polysaccharides (EPS) amount and related genes expression as well as the environmental stresses tolerance. The cell surface was smoother in the AI-2 supplemented treatments than without AI-2. Meanwhile, AI-2 had ability to promote the growth and formation of biofilm by increasing the yield of EPS, the main components of biofilm. The changes in lamC and ftsH gene expression point to altered regulation for hydrolysis process of polysaccharides as well as the potential for enhanced biofilm formation. The presence of AI-2 also significantly improved (p < 0.01) the tolerance of bile salts in L. plantarum, but the same results did not appear in acid tolerance. In conclusion, AI-2 supplementation could improve the biofilm formation and bile salts tolerance in L. plantarum, and this effect was likely modulated by facilitating EPS production and suppression polysaccharides hydrolysis.

细菌中存在群体感应（QS），以相互沟通并以依赖于细胞密度的方式调节群体行为，群体感应使用信号分子自动诱导物2（AI-2）进行种内和种间交流。外源AI-2对植物乳杆菌生物膜形成和环境耐受性的影响是这次审查的重点。对外源AI-2的反应跨越多种生理代谢行为，涉及细菌生长，形态特征，生物膜发育，细胞外多糖（EPS）数量和相关基因表达以及环境胁迫耐受性。在补充AI-2的处理中，细胞表面比没有AI-2的细胞表面光滑。同时，AI-2具有通过增加生物膜主要成分EPS的产量来促进生物膜生长和形成的能力。lamC和ftsH基因表达的变化表明改变了多糖水解过程的调控以及增强生物膜形成的潜力。AI-2的存在也显着改善（p<0.01）在植物乳杆菌中的胆汁盐耐受性，但在耐酸性方面未出现相同的结果。总之，补充AI-2可以改善植物乳杆菌的生物膜形成和胆汁盐耐受性，并且可能通过促进EPS产生和抑制多糖水解来调节这种作用。