Up-Hill Transport of Tryptophan through Polymer Inclusion Membrane Containing Aliquat 336

Tryptophan, which is an essential amino acid, is used as a nutrient enhancer, a preservative, and a feed additive. Development of a cost-effective and straightforward separation technique is still required to extract and purify tryptophan in the bioproduction processes. We conducted permeation of tryptophan through poly(vinyl chloride)-based membrane containing Aliquat 336 as a carrier. Tryptophan successfully permeated through the membranes against its concentration gradient when the feed and receiving solutions were prepared by 0.1 mol/dm3 sodium hydroxide solution and hydrochloric acid, respectively. The up-hill transport of tryptophan was achieved and more than 85% of tryptophan in the feed solution was recovered.