产GABA乳酸菌菌种筛选及其谷氨酸脱羧酶的酶学性质研究

Screening lactic acid bacteria for producing γ-aminobutyric acid and enzymatic properties of glutamate decarboxylase

从现有的商业乳酸菌菌种中筛选出产GABA的菌种,进而对其生长曲线及所产谷氨酸脱羧酶的酶学性质进行了研究。结果表明:该菌种接种时选择种龄为16 h的菌种较为合适,该菌种的谷氨酸脱羧酶的酶活受温度、pH和酶浓度影响较大。最适温度为40℃,在最适温度左右酶的稳定性最好,最适pH为4.5,在pH4.0~5.0时有较高的酶活力,酶浓度不断增大时,酶活上升趋势逐渐变缓。这为利用该乳酸菌进行发酵产GABA的工艺研究提供了参考依据。

The strain for producing γ-aminobutyric acid（GABA） was screened from current commercial lactic acid bacteria, then its growth curve and enzymatic properties of glutamate decarboxylase were studied. The results showed that the strain of seed age 16 h was more appropriate age of inoculating, the enzyme activities of glutamate decarboxylase were greatly affected by temperature, pH value and enzyme concentration. The optimum temperature and pH value were 40 ℃ and 4.5 respectively, the heat stability was best at the optimum temperature and the enzyme activity was higher at pH4.0~5.0. With the increasing of enzyme concentration, the increasing trend of enzyme activity gradually slowed down. This provided a reference for fermentation process of producing GABA by lactic acid bacteria.