Abstract: A lacto-N-triose II crystal form A and a preparation method therefor. The powder X-ray diffraction pattern of the crystal form has characteristic diffraction peaks at diffraction angles (2?±0.2°) of 4.80, 8.32, 9.62, 12.72, 18.67, 19.90, 21.05, and 21.59 degrees. The lacto-N-triose II crystal form A has good moisture absorption resistance and stability, can reduce packaging costs, and prolongs product shelf life.

Abstract: A glycoside hydrolase, relating to the technical field of enzyme engineering/gene engineering. Provided are an enzyme of a GH112 glycoside hydrolase family, and an application of synthesizing human milk oligosaccharides (HMOs) by using an enzyme of a GH112 glycoside hydrolase family. A synthesis reaction is catalyzed by using the enzyme of the glycoside hydrolase family 112 (GH112) that is classified according to a Carbohydrate-Active-Enzymes (CAZy) database (http://www.cazy.org); and lacto-N-tetraose (LNT) is generated in an aqueous solution comprising lactose and/or galactose and/or galactose-1-phosphate and lacto-N-triose (LNTII). The enzyme of the glycoside hydrolase family 112 (GH112), and the preparation method therefor and the application thereof provided by the present invention have economic and social values.