The present disclosure relates to novel D-psicose 3-epimerase and a method for producing psicose using the same.

An allulose 3-epimerase mutant, a genetically engineered bacterium expressing the mutant, and an immobilized allulose 3-epimerase enzyme and an immobilization method thereof are described. A high-throughput screening method is used to obtain an allulose 3-epimerase mutant efficiently expressed in a fermentation process, which can catalyze efficient conversion of fructose to D-allulose, providing an efficient production path for key enzymes required in a D-allulose production process. Additionally, the allulose 3-epimerase is bonded to an immobilizing resin to prepare an immobilized allulose 3-epimerase enzyme. The immobilized enzyme can be applied to batch or continuous reactions to catalyze efficient conversion of fructose to D-allulose.

An allulose 3-epimerase mutant, a genetically engineered bacterium expressing the mutant, and an immobilized allulose 3-epimerase enzyme and an immobilization method thereof are described. A high-throughput screening method is used to obtain an allulose 3-epimerase mutant efficiently expressed in a fermentation process, which can catalyze efficient conversion of fructose to D-allulose, providing an efficient production path for key enzymes required in a D-allulose production process. Additionally, the allulose 3-epimerase is bonded to an immobilizing resin to prepare an immobilized allulose 3-epimerase enzyme. The immobilized enzyme can be applied to batch or continuous reactions to catalyze efficient conversion of fructose to D-allulose.

The present invention provides: a novel allulose epimerase variant in which an amino acid residue present at a specific position of an amino acid sequence of a wild-type D-allulose 3-epimerase derived from Flavonifractor plautii is substituted with another amino acid residue; and various uses of the novel allulose epimerase variant. The novel allulose epimerase variant according to the present invention has a higher conversion rate of fructose to allulose compared to that of the wild-type D-allulose 3-epimerase derived from Flavonifractor plautii, and has excellent thermal stability especially under high temperature conditions of 60° C. or higher, and thus can prevent contamination during an industrial-scale enzymatic conversion reaction for the mass production of allulose, shorten production time, and reduce production costs.

The present invention provides: a novel allulose epimerase variant in which an amino acid residue present at a specific position of an amino acid sequence of a wild-type D-allulose 3-epimerase derived from Flavonifractor plautii is substituted with another amino acid residue; and various uses of the novel allulose epimerase variant. The novel allulose epimerase variant according to the present invention has a higher conversion rate of fructose to allulose compared to that of the wild-type D-allulose 3-epimerase derived from Flavonifractor plautii, and has excellent thermal stability especially under high temperature conditions of 60° C. or higher, and thus can prevent contamination during an industrial-scale enzymatic conversion reaction for the mass production of allulose, shorten production time, and reduce production costs.

The present invention relates to a method for producing trehalose, comprising the steps of mixing and reacting, in any order, (i) at least one alpha-phosphorylase capable of catalyzing the production of alpha-D-glucose 1-phosphate intermediate from a saccharide raw material, and from at least one phosphorus source; (ii) at least one trehalose phosphorylase capable of catalyzing the production of trehalose from an alpha-D-glucose 1-phosphate intermediate and a glucose substrate, wherein the trehalose phosphorylase is a trehalose phosphorylase variant with an amino acid sequence which differs from the amino acid sequence of a wild type trehalose phosphorylase in at least one amino acid position, (iii) at least one saccharide raw material which produces an alpha-D-glucose 1-phosphate intermediate and a co-product by catalytic action of the alpha-phosphorylase; and (iv) at least one phosphorus source selected from the group consisting of a phosphoric acids and an inorganic salt thereof.

The present invention relates to a method for producing trehalose, comprising the steps of mixing and reacting, in any order, (i) at least one alpha-phosphorylase capable of catalyzing the production of alpha-D-glucose 1-phosphate intermediate from a saccharide raw material, and from at least one phosphorus source; (ii) at least one trehalose phosphorylase capable of catalyzing the production of trehalose from an alpha-D-glucose 1-phosphate intermediate and a glucose substrate, wherein the trehalose phosphorylase is a trehalose phosphorylase variant with an amino acid sequence which differs from the amino acid sequence of a wild type trehalose phosphorylase in at least one amino acid position, (iii) at least one saccharide raw material which produces an alpha-D-glucose 1-phosphate intermediate and a co-product by catalytic action of the alpha-phosphorylase; and (iv) at least one phosphorus source selected from the group consisting of a phosphoric acids and an inorganic salt thereof.

The present disclosure relates to a composition for producing tagatose, comprising fructose-6-phosphate-4-epimerase, and a method of producing tagatose using the same.

The present disclosure relates to a composition for producing tagatose, comprising fructose-6-phosphate-4-epimerase, and a method of producing tagatose using the same.

The invention relates to improved processes for the enzymatic production of allulose using enzymes which have been characterized as having improved expression, improved stability, and low allulose to fructose conversion activity, relative to enzymes in other allulose production methods. Improved processes include steps of converting fructose-6-phosphate to allulose 6-phopsphate A6P) using an allulose 6-phosphate epimerase, and converting A6P to allulose using an allulose-6-phosphate phosphatase.