Provided herein, in some embodiments, are systems, methods, and compositions (e.g., cells and cell lysates) for enzymatically converting a polymeric glucose carbohydrate (e.g., starch) to sugar.

The current disclosure provides a process for enzymatically converting a saccharide into allulose. The invention also relates to a process for preparing allulose where the process involves converting fructose 6-phosphate (F6P) to allulose 6-phosphate (A6P), catalyzed by allulose 6-phosphate 3-epimerase (A6PE), and converting the A6P to allulose, catalyzed by allulose 6-phosphate phosphatase (A6PP).

Provided herein, in some embodiments, are systems, methods, and compositions (e.g., cells and cell lysates) for enzymatically converting a polymeric glucose carbohydrate (e.g., starch) to sugar.

The invention relates to immobilized enzyme compositions for the preparation of a hexose. Hexoses include, for example, tagatose, psicose, fructose, allose, mannose, galactose, altrose, talose, sorbose, gulose, idose, and inositol. The invention also relates to an enzymatic process for preparing a hexose from a saccharide by contacting a starch derivative with an immobilized enzyme composition of the invention.

Provided are a biomimetic silicon mineralized microcapsule immobilized multi-enzyme, a preparation method therefor, and a method for producing tagatose by using same. The preparation method comprises the following steps: (1) pre-mixing glucan phosphorylase, phosphoglucomutase, phosphoglucoisomerase, 6-phosphate tagatose 4-position epimerase and 6-phosphate tagatose phosphatase solutions, then adding the mixture to a calcium chloride solution, and then pouring same into a sodium carbonate solution, stirring and separating same to obtain calcium carbonate microspheres containing a multi-enzyme; (2) mixing the calcium carbonate microspheres with a polyethyleneimine solution to obtain polyethyleneimine-calcium carbonate microspheres after separation; (3) mixing the polyethyleneimine-calcium carbonate microspheres with a silicate solution to obtain biomimetic silicon mineralized-calcium carbonate microspheres after separation; and (4) mixing the biomimetic silicon mineralized-calcium carbonate microspheres with ethylenediamine tetraacetic acid for reaction to remove calcium carbonate, and separating same to obtain a biomimetic silicon mineralized microcapsule immobilized multi-enzyme.

In various aspects and embodiments, the invention provides microbial cells and methods for producing advanced glycosylation products from lower glycosylated intermediates. The microbial cell expresses one or more UDP-dependent glycosyl transferase enzymes in the cytoplasm, for glycosylation of the intermediates. When incubating the microbial strain with a plant extract or fraction thereof comprising the intermediates, these glycosylated intermediates are available for further glycosylation by the cell, and the advanced glycosylation products can be recovered from the media and/or microbial cells.

Provided are the immobilization of multiple enzymes on the basis of an artificial oil body and an application thereof in the preparation of tagatose. Specifically, an artificial oil body is used to mix an expressed fusion protein of target protease-oil body protein with an oil body, which then undergoes an ultrasonic treatment; the fusion protein is anchored to the surface of the oil body by means of the specific hydrophobicity of a human protein to form an artificial oil body containing the target protease, so that the purification and immobilization of enzymes can be completed simultaneously. The immobilized multiple enzymes that can be used for tagatose production utilize an artificial oil body as an immobilized enzyme substrate, which significantly improves the stability of the immobilized enzymes, reduces the production cost of the current enzymatic preparation of tagatose, and has a simple preparation process.

The invention discloses a method for improving the yield of Bacillus subtilis acetylglucosamine, which belongs to the technical field of genetic engineering. In the invention, the recombinant Bacillus subtilis S5 (S5-PxylA-glmS-P43-GNA1) is taken as a starting strain, and the glmS ribozyme is integrated into the mid of rbs and the promoter sequence of the glmM and pfkA gene, respectively. The ribozyme mutant has the advantage of prolonging the stability of the mRNA and integrated into the mid of rbs and the promoter sequence of the pgi gene. The yield of GlcNAc of the recombinant strain reaches 11.79-20.05 g/L. This laid the foundation for the further metabolic engineering of Bacillus subtilis to produce GlcNAc.

A recombinant microorganism of the genus Komagataeibacter having enhanced cellulose productivity and yield, a method of producing cellulose using the recombinant microorganism, and a method of producing the recombinant microorganism are provided.

This invention is aimed at improving an ethanol fermentation ability of a recombinant yeast strain having an ability of assimilating pentose, such as xylose or arabinose. The recombinant yeast strain haying an ability of assimilating pentose is obtained by lowering activity of a gene involved in upstream of glyceraldehyde-3-phosphate in the Embden-Meyerhof pathway.