Mutants for the preparation of d-amino acids
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.