D-amino acid oxidase mutants and uses thereof in preparing L-glufosinate

A method for preparing L-glufosinate, comprising:

• generating the L-glufosinate by converting D-glufosinate in the presence of an enzymatic system, wherein the enzymatic system comprises a D-amino acid oxidase mutant for converting the D-glufosinate to 4-(Methylhydroxyphosphinyl)-2-oxobutyric acid;
• and the D-glufosinate is initially present in a racemic mixture of the D-glufosinate and the L-glufosinate or salts thereof, wherein the D-amino acid oxidase mutant has an amino acid substitution at least one of position 62 and position 226 of the amino acid sequence of the D-amino acid oxidase mutant when compared to the amino acid sequence of a D-amino acid oxidase as set forth in SEQ ID NO. 1, the position 62 and position 226 are defined with reference to the SEQ ID NO. 1, and the amino acid sequence of the D-amino acid oxidase mutant has at least 90% identity to the SEQ ID NO. 1.