Aldolase, aldolase mutant, and method and composition for producing tagatose by using same

Abstract

There are provided aldolase, an aldolase mutant, a method for producing tagatose, and a composition for producing tagatose using the same. The technical feature of the present invention is environment-friendly due to the use of an enzyme acquired from microorganisms, requires only a simple process of enzyme-immobilization, uses a low-cost substrate compared with that of a conventional method for producing tagatose, and has a remarkably high yield, thereby greatly reducing production cost while maximizing production effect.

1 . A method of producing tagatose from fructose, the method comprising:
 reacting fructose 6-phosphate with tagatose 6-phosphate epimerase or a mutant thereof to obtain tagatose 6-phosphate; and   converting the tagatose 6-phosphate to tagatose.   
     
     
         2 . The method of  claim 1 , wherein the tagatose 6-phosphate epimerase catalyzes the conversion of fructose 6-phosphate to tagatose-6-phosphate. 
     
     
         3 . The method of  claim 1 , wherein the tagatose 6-phosphate epimerase is SEQ ID NOS: 1. 
     
     
         4 . The method of  claim 1 , wherein the tagatose 6-phosphate epimerase is SEQ ID NOS: 2. 
     
     
         5 . The method of  claim 1 , wherein the tagatose 6-phosphate epimerase is SEQ ID NOS: 3. 
     
     
         6 . The method of  claim 1 , wherein the tagatose 6-phosphate epimerase is SEQ ID NOS: 4. 
     
     
         7 . The method of  claim 1 , wherein the mutant comprises at least one amino acid substitution of SEQ ID NO: 1 selected from the group consisting of:
 i) a substitution of arginine residue with glutamine at a position corresponding to position 332,   ii) a substitution of glutamine residue with alanine at a position corresponding to position 314,   iii) a substitution of histidine residue with alanine at a position corresponding to position 227, and   iv) a substitution of serine residue with alanine at a position corresponding to position 62.   
     
     
         8 . The method of  claim 1 , wherein the fructose 6-phosphate is obtained by treating fructose or a fructose-containing material with hexokinase. 
     
     
         9 . The method of  claim 1 , wherein the tagatose is obtained by treating the tagatose 6-phosphate with phytase. 
     
     
         10 . The method of  claim 1 , wherein the reaction of the fructose 6-phosphate with the tagatose 6-phosphate epimerase is performed at a pH from 7.0 to 9.0. 
     
     
         11 . The method of  claim 1 , wherein the reaction of the fructose 6-phosphate with the tagatose 6-phosphate epimerase is performed at a temperature from 30 ° C. to 70 ° C.