| abstract |
Enzymatic prodn. of L-tryptophan (I) comprises reacting indole (II), pyruvic acid (III) and/or its salt, and an NH4 salt (IV) in presence of tryptophanase (V) in an automatic, computer-controlled system consisting of a bioreactor and device for direct determn. of (II). The computer regulates addn. of reactants and controls the reaction by feedback according to the measured (II) concn. Addn. of (II) and (IV) is controlled according to a predetermined profile, corresp. to the activity profile of (V), and (II) or its salt is added at a specific time. Also new is the automatic, computer-controlled system. |