| 초록 |
GABA acts as an inhibitory neurotransmission in mammalian central nervous system and is widely used as a food supplement. We engineered a GABA producing E.coli through knocking out byproduct pathway related genes and overexpressing modified glutamate decarboxylase which can synthesize GABA under neutral pH condition. However, since the titer of GABA was still low, 13C MFA was conducted to determine metabolic flux ratios of central carbon metabolism. From 13C MFA result, we speculated that if we can optimize fluxes of OAA synthesis via anaplerotic reaction and acetyl-CoA synthesis from pyruvate, increased TCA cycle flux may enhance GABA production as GABA is made from α-KG. We diversified anaplerotic flux by regulating transcription of pyruvate carboxylase, introduced from C. glutamicum, and RT-PCR was conducted to compare transcription levels on different inducer levels. Finally, 13C MFA was carried out to verify optimal central carbon metabolic flux ratios for GABA production. |
