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US 9,175,282 B2Granted
Cellobiose 2-epimerase, its preparation and uses
AssigneeHayashibara Co., Ltd.
InventorsHikaru Watanabe, Masahiro Yagi, Tomoyuki Nishimoto, Hiroto Chaen, Shigeharu Fukuda
Life of this patent
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Abstract
The present invention has objects to provide a thermostable cellobiose 2-epimerase, its preparation and uses. The present invention attains the above objects by providing a thermostable cellobiose 2-epimerase, a DNA encoding the enzyme, a recombinant DNA and transformant comprising the DNA, a process for producing the enzyme, and a process for producing isomerized saccharides using the enzyme.
Claims2
A process for producing an isomerized saccharide selected from the group consisting of D-mannose, D-talose, epimaltose, and epimaltooligosaccharide with a glucose polymerization degree of 3 or higher, comprising the steps of:
- (1) allowing a cellobiose 2-epimerase to act on a material saccharide selected from the group consisting of D-glucose, D-galactose, maltose, and maltooligosaccharide with a glucose polymerization degree of 3 or higher, at a temperature of 55° C. or more, for forming a corresponding isomerized saccharide selected from the group consisting of D-mannose, D-talose, epimaltose, and epimaltooligosaccharide with a glucose polymerization degree of 3 or higher;
- wherein said cellobiose 2-epimerase catalyzes the following isomerizations:
- (a) 2-Epimerization
- epimerizing the 2-hydroxyl group of D-glucose and D-galactose to convert D-glucose and D-galactose into corresponding D-mannose and D-talose, and vice versa;
- epimerizing the 2-hydroxyl group of the reducing end glucose in maltose, cellobiose, and lactose to convert maltose, cellobiose, and lactose into corresponding epimaltose, epicellobiose, and epilactose;
- and
- epimerizing the 2-hydroxyl group of the reducing end glucose in a maltooligosaccharide and cellooligosaccharide, which have a glucose polymerization degree of 3 or higher, to convert the maltooligosaccharide and cellooligosaccharide into corresponding epimaltooligosaccharide and epicellooligosaccharide;
- and
- (b) Aldose-Ketose conversion
- converting D-glucose or D-mannose into D-fructose, and vice versa;
- converting D-galactose or D-talose into D-tagatose, and vice versa;
- converting maltose or epimaltose into maltulose;
- converting cellobiose or epicellobiose into cellobiulose;
- and
- converting lactose or epilactose into lactulose;
- and
- (2) decolorizing, deionizing, and concentrating the isomerized saccharide formed in step (1),
- wherein said cellobiose 2-epimerase is selected from the group consisting of a cellobiose 2-epimerase having the amino acid sequence of SEQ ID NO:10 and a recombinant cellobiose 2-epimerase having a variant amino acid sequence of SEQ ID NO:10, where one or more but less than 10 amino acid residues in SEQ ID NO:10 are replaced, deleted, or added without altering the enzyme activities in (a) and (b).
15 more elements
A process for producing isomerized saccharide selected from the group consisting of D-fructose, D-tagatose, maltulose, cellobiulose, and lactulose, comprising the steps of:
- (1) allowing a cellobiose 2-epimerase to act on a material saccharide selected from the group consisting of D-glucose, D-galactose, maltose, cellobiose, and lactose, at a temperature of 55° C. or more for forming a corresponding isomerized saccharide selected from the group consisting of D-fructose, D-tagatose, maltulose, cellobiulose, and lactulose;
- wherein said cellobiose 2-epimerase catalyzes the following isomerizations:
- (a) 2-Epimerization
- epimerizing the 2-hydroxyl group of D-glucose and D-galactose to convert D-glucose and D-galactose into corresponding D-mannose and D-talose, and vice versa;
- epimerizing the 2-hydroxyl group of the reducing end glucose in maltose, cellobiose, and lactose to convert maltose, cellobiose, and lactose into corresponding epimaltose, epicellobiose, and epilactose;
- and
- epimerizing the 2-hydroxyl group of the reducing end glucose in a maltooligosaccharide and cellooligosaccharide, which have a glucose polymerization degree of 3 or higher, to convert the maltooligosaccharide and cellooligosaccharide into corresponding epimaltooligosaccharide and epicellooligosaccharide;
- and
- (b) Aldose-Ketose conversion
- converting D-glucose or D-mannose into D-fructose, and vice versa;
- converting D-galactose or D-talose into D-tagatose, and vice versa;
- converting maltose or epimaltose into maltulose;
- converting cellobiose or epicellobiose into cellobiulose;
- and
- converting lactose or epilactose into lactulose;
- and
- (2) decolorizing, deionizing, and concentrating the isomerized saccharide formed in step (1),
- wherein said cellobiose 2-epimerase is selected from the group consisting of a cellobiose 2-epimerase having the amino acid sequence of SEQ ID NO:10, and a recombinant cellobiose 2-epimerase having a variant amino acid sequence of SEQ ID NO:10, where one or more but less than 10 amino acid residues in SEQ ID NO:10 are replaced, deleted, or added without altering the enzyme activities in (a) and (b).
15 more elements
Dependencies are inferred from the claim text.