Production method of L-phosphinothricin

The invention discloses a production method of L-phosphinothricin. According to the method, 2-carbonyl-4-(hydroxymethylphosphonyl)butyric acid is used as a substrate and is catalyzed by an enzyme catalytic system to obtain L-phosphinothricin, and the enzyme catalytic system is composed of gamma-aminobutyric acid/alpha-ketoglutarate transaminase, glutamate dehydrogenase and a coenzyme regeneration system. The method utilizes the advantages of high catalytic activity, strong stereoselectivity and the like of transaminase, and also solves the problem of incomplete transaminase catalytic reaction, so that the catalytic reaction can completely convert the substrate 2-carbonyl-4-(hydroxymethylphosphonyl)butyric acid into L-phosphinothricin, and the conversion rate can reach 100%; no by-product alpha-ketoglutarate is accumulated in the final product of the method, and the residual amount of other substances such as the raw material glutamic acid in the product after the end of the reaction is extremely low, so the subsequent refining process of L-phosphinothricin is greatly simplified, and the total yield of the product is increased.