Study on innovated continuous chromatographic process to separate L-tryptophan

The separation and purification of L-tryptophan fermentation broth is an important factor forthe production cost of L-tryptophan industry.This study is aiming to develop an innovative chromatographic process to isolate L-tryptophan from fermentation broth in order to reduce the purification cost and increase the recovery of L-tryptophan. Continuous chromatographic process for L-tryptophan separation was set up by use of resin screening and sequential simulated moving bed ( SSMB) technology.Based on dynamic capacity of L-tryptophan on different resin, cation IEX resin of Applexion XA2014-22 was selected as the best one with dynamic capacity of 120 g L-Trp/L resin.After SSMB separation, 80% purity of L-tryptophan was obtained starting from 30% purity of raw material with selected resin and eluent by elution test. The final yield of L-tryptophan reached 99%, and all of the glutamic acid of raw material was removed.Compared with the traditional ion exchange process, this study provided an effective and economical technology for the separation and purification of L-tryptophan in industrial production.