Mutants for the preparation of D-amino acids

摘要

Escherichia. 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 and include those which produce D-amino acids via the carbamoylase/hydantoinase route.

主权项

1. An isolated Escherichia coli strain
having its dadA gene mutated or deleted so that said gene does not express a functional D-amino acid oxidase; and having its dsdA gene mutated or deleted so that said gene does not express a functional D-serine dehydratase; wherein said strain has been transformed with and expresses a D-carbamoylase gene and a D-hydantoinase gene, wherein the strain is Escherichia coli strain DSM15182 (ET4), and wherein the isolated strain exhibits reduced breakdown of produced D-amino acids when cultured in a suitable medium.