Preparation Of γ-aminobutyric Acid By Two Methods

γ-amino butyric acid (GABA), a well-studied inhibitory neurotransmitter, is involved in lots of metabolic activities. Previous studies showed that GABA not only has the ability to sedative nerve, to decline blood pressure, but also can be used in the therapy of some mental diseases.For preparation ofγ-aminobutyric acid, two methods including chemical synthesis and biological transformation were employed individually in this study. By means of chemical synthesis, the preparation was carried out with 2-pyrrolidone as raw materials under the alkaline condition of KOH, the conversion rate could reach 95% or more. With the biological method, the bacterial strain screened out from yogurt was preliminary identified as bacterium Lactococcus, GABA was produced by fermentation with sodium glutamate as raw materials. The concentration of final product could reach about 3.9g/LFor desalt from GABA-potassium bipolar membrane electro-dialysis(BMED) method is investigated in more detail. By using a three-compartment BMED, GABA and KOH from its salt could be separated individually. Moreover, GABA crystal can be collected when the GABA solution is cooled down. The purity of GABA can exceed 99%. Standing on the economic view, for full processing, the average electric current efficiency was above 60%, the electric energy consumption was approximately 2kWh per kg of GABA.