Abstract:Lactic acid bacteria biofilm has various physical properties and physiological functions such as adhesion, resistance and antibacterial activity. It is widely used in improving the texture of food and in the biological preservation of food. The formation of lactic acid bacteria biofilm needs five stages as attachment, formation, maturation, aging off and reattachment, and is regulated by the quorum sensing system. Quorum sensing system (QS) is a widespread gene expression regulatory system in bacteria, which regulates the physiological functions of bacteria by targeting the expression of related genes through signaling molecules. The LuxS/AI-2 type QS is the main QS for regulating the probiotic properties of lactic acid bacteria. Understanding the LuxS/AI-2 type QS of lactic acid bacteria and its mechanism of regulating biofilm formation is crucial for further applications of lactic acid bacteria in the food industry. The recent research progress on the formation processes of lactic acid bacteria biofilms, and the five regulatory elements of LuxS/AI-2 type QS regulating lactic acid bacteria biofilm formation, including the signaling molecule AI-2 (autoinducer-2), key regulatory genes (luxS, tuf, fba, gap), key regulatory proteins (LuxS, LacI, AraC, PadR, and Rbs family proteins), the possible receptor proteins of signaling molecule AI-2 (LuxP, LsrB, RbsB and the dCACHE domains receptor proteins) and key metabolic pathways was highlighted. Furthermore, the possible molecular mechanisms of signal molecule AI-2 regulating biofilm formation of lactic acid bacteria, as well as the screening strategy of signal molecule AI-2 receptor protein were summarized. The aim of study was to provide a theoretical guide to gain insight into the LuxS/AI-2 type QS that regulates the biofilm formation of lactic acid bacteria.