PREPARATION OF PREPHENIC ACID AND ITS CONVERSION TO PHENYLALANINE AND TYROSINE BY PLANT ENZYMES

Abstract
Enzymes from mung bean (Phaseolus aureus Roxb.) convert prephenic acid to phenylalanine and tyrosine. In addition to glutamate NADP was required for the production of tyrosine but no cofactor appeared necessary for the formation of phenylalanine. Prephenic acid was produced by growing the auxotroph, Escherichia coli, 58-278, in 20 liters of medium in fermenters at 30 °C. From 275 to 325 mg of prephenic acid was obtained per liter. The culture nitrates were concentrated, and the prephenic acid adsorbed and eluted from Dowex 1 resin and charcoal before being recovered in 40–50% yield as the crystalline barium salt.