| 摘要 |
PURPOSE:In preparing L-tryptophan using a bacterium, to obtain purified L- tryptophan, by treating crude L-tryptophan with active carbon using a specific volume of water-containing isopropyl alcohol, recrystallizing it. CONSTITUTION:For example, L-tryptophan is synthesized from L-serine and indole in the presence of Excherichia coli. Crude L-tryptophan is obtained from the reaction solution containing L-tryptophan and Escherichia coli. The crude tryptophan is blended with 14-20 (especially 14.5-16 times by weight times) as much 30-60vol% water-containing isopropyl alcohol as the crude tryptophan by weight and 0.1-10 times as much active carbon as it is added to it. The solution is stirerd at the boiling point until L-tryptophan is sufficiently dissolved, filtered while it is hot, and the filtrate is cooled to precipitate purified L-tryptophan. |
