Glucansucrase Produced by Lactic Acid Bacteria: Structure, Properties, and Applications

Glucansucrase (GS) belongs to the GH70 family, which not only can synthesize exopolysaccharides (EPSs) with different physicochemical properties through glucosyl transglycosylation (by hydrolyzing sucrose) but can also produce oligosaccharides. Different strains produce different GSs, which catalyze the synthesis of EPS with different glycosidic bond structures; these EPSs have different biological functions. As an important enzymatic tool, GS has great potential in health care medicine, biological materials, ecological protection, the food chemical industry, etc. GS is mainly produced by lactic acid bacteria (LAB), including Leuconostoc, Streptococcus, Lactobacillus, and Weissella species. With the elucidation of the crystal structure of GS and the advancement of genome sequencing technology, its synthesis reaction mechanism and specific structural characteristics are gradually becoming clear. This review summarizes the isolation, purification, physical and chemical properties, detection methods, sources, and applications of GS in order to provide a reference for the research and development of GS.