Process for preparing L-tryptophan.

摘要

A method of preparing L-tryptophan by reacting indole and serine and using an aqueous solution of enzymes which are extracted from cells. After the reaction, the pH value of the reaction mass is adjusted to above 10 by ammonia. The L-tryptophan can be dissolved in the solution in a high concentration, so purification and separation are facilitated and the loss of L-tryptophan minimalized. The preparation of a stable aqueous solution of enzymes is also provided wherein an extracted enzyme solution is heated above 40 DEG C.