Mutants for the preparation of d-amino acids

Abstract

The present invention relates to specific E. coli mutants which can be used for the synthesis of D-amino acids, and to such a process. The mutants are distinguished by deficiencies in particular enzymes which break down D-amino acids.

1 . A recombinant microorganism for the preparation of D-amino acids starting from N-carbamoylamino acids or 5-monosubstituted hydantoins in which the gene which codes for a D-amino acid oxidase and/or the gene which codes for a D-serine dehydratase is inactivated by mutagenesis.  
     
     
         2 . The recombinant microorganism according to  claim 1 , wherein the recombinant microorganism is an organism of the genus  Escherichia coli.    
     
     
         3 . The recombinant microorganism according to  claim 1  wherein the recombinant microorganism has a D-carbamoylase gene from  Agrobacterium  sp.,  Arthrobacter  sp. or  Bacillus  sp.  
     
     
         4 . The recombinant microorganism according to  claim 2  wherein the recombinant microorganism is  Escherichia coli  DSM 15181 and mutants derived therefrom.  
     
     
         5 . The recombinant microorganism according to  claim 2  wherein the recombinant microorganism is  Escherichia coli  DSM 15182 and mutants derived therefrom.  
     
     
         6 . A process for the preparation of D-amino acids comprising utilizing the recombinant microorganism according to  claim 1 .  
     
     
         7 . The process according to  claim 6 , wherein D-aminobutyric acid, D-serine, D-methionine, D-tryptophan and D-phenylalanine are prepared.  
     
     
         8 . A process for the preparation of D-amino acids comprising utilizing the recombinant microorganism according to  claim 2 .  
     
     
         9 . The process according to  claim 8  wherein D-aminobutyric acid, D-serine, D-methionine, D-tryptophan and D-phenylalanine are prepared.