Isolation and Purification of γ-aminobutyric Acid from Reaction Solution of Glutamic Acid by Ion-exchange Resins

The immobilized glutamate decarboxylase can transform glutamic acid into γ-aminobutyric acid.Four types of acid cation resins were selected to separate γ-aminobutyric acid from the transformation reaction solution of glutamic acid,in which D061 has the maximal γ-aminobutyric acid exchange capacity.Through static and dynamic experiments,different operating conditions in the fixed bed to separate γ-aminobutyric acid were investigated.The results showed that the optimum parameters were as follows:temperature at 40 ℃,adsorption balance time 17 min and pH 4 in the static experiment.The dynamic experimental results showed that the optimal adsorptive flow rate was 1 BV/h in a column.The elution conditions were optimized that 1.2 mol/L of aqueous ammonia brought an efficient elution at a flow rate of 1.0 BV/h.The white needle crystal of γ-aminobutyric acid was obtained after the effluent of γ-aminobutyric acid was concentrated,crystallized and dried.The total recovery rate was 80%.The sample was testified by X-ray diffraction patterns.