Enzymatic Production of γ-Aminobutyric Acid Using Rice Bran

An enzymatic method for gamma-aminobutyric acid (GABA) production was invested. With this method, rice bran was used as glutamate decarboxylase (GAD) source and exogenous monosodium glutamate(MSG) was used as substrate. We stimulated the rice bran GAD via regulating the temperature, pH, reaction time, buffer and adding PLP, Ca2+ and substrate. In the existence of PLP and Ca2+, the GABA content of rice bran had been improved by about 45 fold. The GABA production reached 2.3g/100g bran, and the Glu conversion reached 100%. As rice bran is a by-product in rice processing and a large quantity of rice bran is commercially available, our study illuminated a safe and efficient way to produce GABA and GABA enriched food.