Sodium Hydroxide → L-Tryptophan

Participants

Reaction Steps

An aqueous solution of 130 g of the L-tryptophan hydrochloride crystals at a concentration of 150 g/l and 27% aqueous sodium hydroxide solution were simultaneously fed into a crystallization tank at 30° C., while controlling the feeding rate of each solution so that the pH of the crystallization slurry was maintained at 6.5. After addition of the solution of L-tryptophan hydrochloride was completed, the crystallized L-tryptophan was isolated with a centrifuging machine. The crystals were then washed with water, and dried at 60° C. for 2 hours under reduced pressure to give 92 g of L-tryptophan crystals. The L-tryptophan crystals thus obtained had a purity of 96.4%, corresponding to a yield of 75% of L-tryptophan from that produced in the fermentation broth.

Provenance & Evidence