In this study, the effect of glutamate decarboxylase from Pyrococcus horikoshii on gamma-aminobutyric acid (GABA) production was investigated in Escherichia coli for the first time. E. coli with overexpressed P. horikoshii glutamate decarboxylase was cultured at various pH levels and temperatures to determine the optimum conditions for GABA production. The highest final GABA concentration, 5.07 g/L, was obtained from 10 g/L of monosodium glutamate (MSG) with a GABA yield of 83% at 30°C and pH 3.5. When P. horikoshii glutamate decarboxylase was introduced into a GABA aminotransferase knock-out E. coli XBT strains, 5.69 g/L of GABA was produced with a GABA yield of 93%.
Bibliographical noteFunding Information:
This work was supported by a grant from the Next-Generation BioGreen 21 Program (SSAC, grant number: PJ00954904), Rural Development Administration, Republic of Korea.
- Escherichia coli
- Pyrococcus horikoshii
- gamma-aminobutyric acid
- glutamate decarboxylase