Yu Ping, Chen Kaifei, Huang Xingxing, Wang Xinxin, Ren Qian
a College of Food Science and Biotechnology , Zhejiang Gongshang University , Hangzhou , Zhejiang Province , People's Republic of China.
Prep Biochem Biotechnol. 2018;48(10):906-913. doi: 10.1080/10826068.2018.1514519. Epub 2018 Sep 28.
The compound γ-aminobutyric acid (GABA) has many important physiological functions. The effect of glutamate decarboxylases and the glutamate/GABA antiporter on GABA production was investigated in Escherichia coli. Three genes, gadA, gadB, and gadC were cloned and ligated alone or in combination into the plasmid pET32a. The constructed plasmids were transformed into Escherichia coli BL21(DE3). Three strains, E. coli BL21(DE3)/pET32a-gadA, E. coli BL21(DE3)/pET32a-gadAB and E. coli BL21(DE3)/pET32a-gadABC were selected and identified. The respective titers of GABA from the three strains grown in shake flasks were 1.25, 2.31, and 3.98 g/L. The optimal titer of the substrate and the optimal pH for GABA production were 40 g/L and 4.2, respectively. The highest titer of GABA was 23.6 g/L at 36 h in batch fermentation and was 31.3 g/L at 57 h in fed-batch fermentation. This study lays a foundation for the development and use of GABA.
化合物γ-氨基丁酸（GABA）具有许多重要的生理功能。在大肠杆菌中研究了谷氨酸脱羧酶和谷氨酸/GABA反向转运体对GABA产生的影响。将gadA、gadB和gadC这三个基因单独或组合克隆并连接到质粒pET32a中。将构建好的质粒转化到大肠杆菌BL21(DE3)中。筛选并鉴定了三株菌株，即大肠杆菌BL21(DE3)/pET32a-gadA、大肠杆菌BL21(DE3)/pET32a-gadAB和大肠杆菌BL21(DE3)/pET32a-gadABC。在摇瓶中培养的这三株菌株产生的GABA各自的效价分别为1.25、2.31和3.98 g/L。GABA产生的底物最佳效价和最佳pH分别为40 g/L和4.2。分批发酵36 h时GABA的最高效价为23.6 g/L，补料分批发酵57 h时为31.3 g/L。本研究为GABA的开发和利用奠定了基础。
