γ-Aminobutyric acid (GABA), which can be produced from the metabolism precurosor of glutamate decarboxylase (GAD), L-glutamate or L-MSG, is a kind of non-protein, natural exist amino acids. It has proved that GABA was a very important rejection capability neurotransmitter in the central nerve system of mammalian. GABA has several physiological functions such as hypotensive activity, anti-hyperspasmia, prevention and treatment of epilepsy and activating liver and kidney function. the production and t...