PURPOSE: To improve the production efficiency of L-tryptophan in an enzymatic reaction using indole as a substrate, by adding natural oil and fat to the reaction system.
CONSTITUTION: Escherichia coli YK2004 (FERM P-8328) capable of producing tryptophan synthase and Aeromonas hydrophila subspecies hydrophila (IFO 12658) capable of producing tryptophanase, etc., are cultured in a nutrient medium at 20W50°C for 5hrW3 day under neutral or slightly alkaline pH condition to obtain wet cells of each strain. Wet calls containing tryptophan synthase is added with 0.1W20% indole and L- or DL-serine and 0.1W5% natural oil and fat such as rapseed oil, soybean oil, etc., and made to react with each other in an aqueous solution of 7W9pH at 30W40°C for 1W72hr to obtain the titled amino acid. The titled amino acid can be produced also from the tryptophanase containing wet cell, indole and a pyruvic acid salt.
TERASAWA MASATO
YUGAWA HIDEAKI
SETO TAKATOSHI
IWANE HIROSHI
IMANARI MAKOTO
