Biochemical\nCharacterization of a β‑1,3-Glucanase from Bacteroidetes sp. Having Transglycosylase Activity\nSuitable to Synthesize β‑Glucooligosaccharides

β-1,3-Glucanases have prospective applications\nin areas such\nas functional oligosaccharide preparation, plant protection, and breweries.\nIn this study, a glycoside hydrolase (GH) family 17 β-1,3-glucanase\n(BbGlc17A) from <i>Bacteroidetes</i> bacterium from a microbial\nmat metagenome from the Great Salt Lake was identified. BbGlc17A catalyzed\nthe hydrolytic conversion of laminarin into β-glucooligosaccharides\nwith polymerization degrees of 3–8. The optimal catalytic conditions\nof BbGlc17A were pH 6.5 and 30 °C. In addition to its hydrolytic\nactivity, BbGlc17A also exhibited transglycosidase activities, involving\ncatalysis of the formation of new β-1,6-glycosidic bonds. BbGlc17A\nexhibits the classic (β/α)8 TIM-barrel structure and possesses\nan elongated catalytic groove, distinguishing it from other typical\nβ-1,3-glucanases, which promote the forward direction of the\ntransglycoside reaction. This effectively highlights the potential\nof the enzyme to convert β-1,3-glucan into mixed functional\noligosaccharides. These results reveal the catalytic properties and\nthe application potential of the GH family 17 β-1,3-glucanase\nand provide valuable information about the group of carbohydrate-active\nenzymes in biochemistry.