Microbiological synthesis of L-tryptophan and its related amino acids

Crystalline tryptophanase from Proteus rettgeri was shown to catalyze the synthesis of L-tryptophan from pyruvate, ammonia and indole, at maximum velocity approaching that of the degradative reaction. Based on the results obtained with the crystalline tryptophanase, an enzymatic method for preparation of L-tryptophan and its related amino acids was developed. The cells of Proteus rettgeri containing high enzymatic activity were used directly as the enzyme. This method is simple and is one of the most economical processes to date for preparing L-tryptophan related amino acids from starting materials: sodium pyruvate, indole and its derivatives.