Xylitol dehydrogenase of acetic acid bacteria and gene thereof

Abstract

Xylitol is produced by allowing xylitol dehydrogenase or cells instoduced with a DNA coding for xylitol dehydrogenase, which is a protein of the following (A) or (B) to act on D-xylulose, and collecting produced xylitol: (A) a protein which has the amino acid sequence of SEQ ID NO: 4; (B) a protein which has the amino acid sequence of SEQ ID NO: 4 including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.

What is claimed is:  
     
         1 . A protein defined in the following (A) or (B): 
 (A) a protein which has the amino acid sequence of SEQ ID NO: 4;    (B) a protein which has the amino acid sequence of SEQ ID NO: 4 in Sequence Listing including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.    
     
     
         2 . A protein defined in the following (C) or (D): 
 (C) a protein which has the amino acid sequence of SEQ ID NO: 6;    (D) a protein which has the amino acid sequence of SEQ ID NO: 6 including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.    
     
     
         3 . A DNA which codes for a protein defined in the following (A) or (B): 
 (A) a protein which has the amino acid sequence of SEQ ID NO: 4;    (B) a protein which has the amino acid sequence of SEQ ID NO: 4 including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.    
     
     
         4 . A DNA which codes for a protein defined in the following (C) or (D): 
 (C) a protein which has the amino acid sequence of SEQ ID NO: 6;    (D) a protein which has the amino acid sequence of SEQ ID NO: 6 including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.    
     
     
         5 . The DNA of    claim 3   , which is a DNA defined in the following (a) or (b): 
 (a) a DNA which contains at least a nucleotide sequence corresponding to nucleotide numbers 25 to 1053 of the nucleotide sequence of SEQ ID NO: 3;    (b) a DNA which is hybridizable with a DNA having a nucleotide sequence corresponding to nucleotide numbers 25 to 1053 of the nucleotide sequence of SEQ ID NO: 3 or a probe prepared from the nucleotide sequence under a stringent condition, and codes for a protein having xylitol dehydrogenase activity.    
     
     
         6 . The DNA of    claim 5   , the stringent condition is a condition in which washing is performed at 60° C., and at a salt concentration corresponding to 1×SSC and 0.1% SDS.  
     
     
         7 . The DNA of the    claim 4   , which is a DNA defined in the following (c) or (d): 
 (c) a DNA which contains at least a nucleotide sequence corresponding to nucleotide numbers 1063 to 1848 of the nucleotide sequence of SEQ ID NO: 5;    (d) a DNA which is hybridizable with a DNA having a nucleotide sequence corresponding to nucleotide numbers 1063 to 1848 of the nucleotide sequence of SEQ ID NO: 5 or a probe prepared from the nucleotide sequence under a stringent condition, and codes for a protein having xylitol dehydrogenase activity.    
     
     
         8 . The DNA of    claim 7   , the stringent condition is a condition in which washing is performed at 60° C., and at a salt concentration corresponding to 1×SSC and 0.1% SDS.  
     
     
         9 . A cell which is introduced with a DNA of any one of    claims 3    to    8    in such a manner that xylitol dehydrogenase encoded by the DNA can be expressed.  
     
     
         10 . A method for producing xylitol dehydrogenase, which comprises cultivating the cell of    claim 9    in a medium so that xylitol dehydrogenase should be produced and accumulated in the medium, and collecting xylitol dehydrogenase from the medium.  
     
     
         11 . A method for producing xylitol, which comprises allowing xylitol dehydrogenase of    claim 1    or    2    to act on D-xylulose, and collecting produced xylitol.  
     
     
         12 . A method for producing xylitol, which comprises allowing the cell of    claim 9    to act on D-xylulose, and collecting produced xylitol.