The invention discloses a method for preparing L-phosphinothricin through de-
racemization by a biological
enzyme method, a phosphinothricin
dehydrogenase mutant and an application. According to the method for preparing L-phosphinothricin through de-
racemization by a biological
enzyme method, D,L-phosphinothricin is used as a
raw material, through
catalysis with a multienzyme
catalysis system, theL-phosphinothricin is obtained, wherein the
enzyme catalysis system comprises D-
amino acid oxidase which is used for catalyzing D-phosphinothricin in the D,L-phosphinothricin into 4-(hydroxymethylphosphinyl)-2-oxobutanoic, and the phosphinothricin
dehydrogenase mutant which is used for performing catalytic reduction on the 4-(hydroxymethylphosphinyl)-2-oxobutanoic to obtain the L-phosphinothricin,the phosphinothricin
dehydrogenase mutant is obtained through
mutation of phosphinothricin dehydrogenase in wild mushrooms Thiopseudomonas denitrificans, and a
mutation site is V377S. The phosphinothricin dehydrogenase mutant disclosed by the invention has better catalysis efficiency, when a catalytic reaction is performed by using racemation D,L-phosphinothricin as a substrate, the conversion rate is far higher than that of a catalytic reaction performed by using a
wild type enzyme as a substrate, and the PPO yield is also substantially increased.