• KSBB Journal
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• 제27권2호
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• pp.127-130
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• 2012

In this study, the effects of pH, temperature, IPTG concentration and substrate (MSG) concentration on gamma-aminobutyric acid (GABA) production in engineered Escherichia coli were investigated. Glutamate decarboxylase and glutamate/GABA antiporter were overexpressed in GABA aminotransferase knock-out strain for GABA production. The result of optimization study showed the GABA bioconversion was optimized at pH 3.5, $30^{\circ}C$, 0.5 mM IPTG, 10 g/L MSG. At this condition, 5.23 g/L of final GABA concentration of was achieved from 10 g/L of MSG, which corresponded to a GABA yield of 85.77%.

• 한국식품과학회지
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• 제24권4호
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• pp.315-319
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• 1992

제주도 다원에서 생산된 녹차 생엽을 적채 시기별(1번차, 2번차, 3번차)로 혐기적으로 처리하여, ${\gamma}-aminobutyric$ acid(GABA) 및 기타 주요성분의 함량변화를 측정한 결과 차엽의 질소가스 치환처리 및 진공처리 모두 GABA와 alanine의 함량은 현저하게 증가한 반면에 glutamic acid는 현저하게 감소하였다. 또한 theanine, arginine, caffein 및 polyphenol의 함량은 거의 변화가 없었으며, vit.C의 함량은 혐기처리 시간의 경과에 따라 조금씩 감소하는 것으로 나타났다. 혈압강하작용 성분인 GABA의 생성량은 원엽의 아미노산의 함량, 특히 glutamic acid의 함량에 비례하였으며, 최적 혐기처리 시간은 약 12시간으로 나타났다. 한편, 차엽의 혐기적 처리조건에 있어서 질소가스 치환 처리와 진공처리 사이의 효과에 있어서의 차이는 거의 없었다.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.710-716
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• 2016

Gamma-aminobutyric acid (GABA) is a non-protein amino acid, which is an important inhibitor of neurotransmission in the human brain. GABA is also used as the precursor of biopolymer Nylon-4 production. In this study, the carbon flux from the tricarboxylic acid cycle was directed to the GABA shunt pathway for the production of GABA from glucose. The GABA shunt enzymes succinate-semialdehyde dehydrogenase (GabD) and GABA aminotransferase (GabT) were co-localized along with the GABA transporter (GadC) by using a synthetic scaffold complex. The co-localized enzyme scaffold complex produced 0.71 g/l of GABA from 10 g/l of glucose. Inactivation of competing metabolic pathways in mutant E. coli strains XBM1 and XBM6 increased GABA production 13% to reach 0.80 g/l GABA by the enzymes co-localized and expressed in the mutant strains. The recombinant E. coli system developed in this study demonstrated the possibility of the pathway of the GABA shunt as a novel GABA production pathway.

• KSBB Journal
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• 제15권6호
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• pp.615-620
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• 2000

본 연구에서 현미의 발아에 키토산을 활용함으로써 곰팡이 발생을 억제하고 기능성 생리활성 물질인 GABA의 생성을 증진시 킬 수 있음을 확인하였다. 100 ppm 키토산액에서 72시간 발아 는 현미파우더 그램당 1,035 nmole의 GABA를 보유하게 되어, 발아되지 않은 현미의 136 nmole, 불침종 발아 현미의 771 nmole, 100 ppm 젖산침종 발아 현미의 728 nmole GABA에 비하여 높은 것으로 조사었다. 발아에 의한 GABA 생성증진과 더불어 알라년의 생성증진 및 글루탐산, 아스파틱산, 세련의 함량 감소가 뚜렸하였다. 키토산처리에 의한 GABA의 생성 증진은 GABA 생성에 관여하는 글루탐산 탈탄산효소의 활성증진이 기여한 것 으로 조사되었다. 키토산액에서의 침종 발아는 물침종 발아나 젖산침종 발아에 비하여 곰팡의 발생빈도를 현저하게 낮추었다. 이들결과를 종합할 때 발아현미 제조시 키토산액을 사용하면 기 능성 물질인 GABA 함량이 증진되고 곰팡이등의 잡균의 오염을 줄힐 수 있어 양질의 발아현미를 얻을 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.783-791
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• 2022

Gamma-aminobutyric acid (GABA) improves various physiological illnesses, including diabetes, hypertension, depression, memory lapse, and insomnia in humans. Therefore, interest in the commercial production of GABA is steadily increasing. Lactic acid bacteria (LAB) have widely been reported as a GABA producer and are safe for human consumption. In this study, GABA-producing LAB were preliminarily identified and quantified via GABase assay. The acid and bile tolerance of the L. plantarum FBT215 strain were evaluated. The one-factor-at-a-time (OFAT) strategy was applied to determine the optimal conditions for GABA production using HPLC. Response surface methodology (RSM) with Box-Behnken design was used to predict the optimum GABA production. The strain FBT215 was shown to be acid and bile tolerant. The optimization of GABA production via the OFAT strategy resulted in an average GABA concentration of 1688.65 ± 14.29 ㎍/ml, while it was 1812.16 ± 23.16 ㎍/ml when RSM was applied. In conclusion, this study provides the optimum culture conditions for GABA production by the strain FBT215 and indicates that L. plantarum FBT215 is potentially promising for commercial functional probiotics with health claims.

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.562-568
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• 2006

GABA $(\gamma-aminobutyric\;acid)$ is the principal inhibitory neurotransmitter in the brain. For the efficient production of GAB A, a semi continuous cell entrapment system using Lactobacillus brevis GABA 057 was optimized, including the substrate concentration, bead-stabilizing additives, and reaction conditions. The converted monosodium glutamate (MSG), which was added as a substrate for glutamic acid decarboxylase (GAD), increased from 2% (w/v) to 12% (w/v). The addition of isomaltooligosaccharide to the alginate beads also increased the stability of the entrapped L. brevis and GABA productivity. Consequently, when optimal conditions were applied, up to 223 mM GABA could be produced from 534 mM MSG after 48 h of reaction by using alginate-beadencapsulated L. brevis GABA 057.

• 약학회지
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• 제43권3호
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• pp.300-305
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• 1999

A sensitive and efficient assay method was applied to determine the level of glutamic acid (GA) and ${\gamma}-aminobutyric$ acid (GABA) in frontal cortex and hippocampus of rat administrated with ethanol and drugs. The compounds were derivatized with ο-phthalaldehyde (OPA) and 2-mercaptoethanof for precolunm analysis. The condition for the simultaneous determination of GA, GABA and $\beta-aminobutyric$ acid (BABA) by high performance liquid chromatography with electrochemical detection was reverse phase $C_{18}$ column as stationary phase, 0.1 M phosphate buffer containing 0.1 mM $Na_4EDTA$ : methanol = 55:45 (v+v) pH 3.8 as mobile phase and 0.7V electrode voltage. The stability of reaction product of GA, GABA and BABA with OPA could be increased by adding the same volume of polyethylene glycol 400 to reaction mixture. The GABA level in frotal cortex of rat was significantly decreased by the administration of picrotoxin and diazepam, but it was significantly increased by the administration of red ginseng total saponin, N-methyl-D-glucamine and (-)-deprenyl.

• 한국식품조리과학회지
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• 제29권6호
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• pp.671-677
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• 2013

The objective of this study was to examine the levels of free amino acids and identify the correlation between ${\gamma}$-aminobutyric acid (GABA)and L-glutamic acid contents in Kimchi during fermentation. During 2 weeks of fermentation, the acidity of Kinchi increased, i.e., the pH level decreased from 5.24 to 4.40. The content of amino acids determined using HPLC differed significantly (p < 0.05) during 7 weeks of fermentation. Over the 7 weeks of fermentation, the content of most free amino acids increased in the order L-valine > L-glutamic acid > L-glycine, except L-methionine decreased. Initially, the GABA content was found to be $72.43{\mu}M/100g$ fresh weight (fw), and it increased to $229.06{\mu}M/100g$ fw after 7 weeks. This rapid increase in the GABA content in the initial stage is considered to be due to L-glutamic acid. However, during the period of 0~7 weeks, no correlations were found between the L-glutamic acid and GABA contents.

• Journal of Microbiology and Biotechnology
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• 제27권9호
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• pp.1664-1669
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• 2017

Gamma-aminobutyric acid is a precursor of nylon-4, which is a promising heat-resistant biopolymer. GABA can be produced from the decarboxylation of glutamate by glutamate decarboxylase. In this study, a synthetic scaffold complex strategy was employed involving the Neurospora crassa glutamate decarboxylase (GadB) and Escherichia coli GABA antiporter (GadC) to improve GABA production. To construct the complex, the SH3 domain was attached to the N. crassa GadB, and the SH3 ligand was attached to the N-terminus, middle, and C-terminus of E. coli GadC. In the C-terminus model, 5.8 g/l of GABA concentration was obtained from 10 g/l glutamate. When a competing pathway engineered strain was used, the final GABA concentration was further increased to 5.94 g/l, which corresponds to 97.5% of GABA yield. With the introduction of the scaffold complex, the GABA productivity increased by 2.9 folds during the initial culture period.

• 한국식품과학회지
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• 제34권4호
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• pp.737-740
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• 2002

홍국의 혈압강화효능과의 관련성이 시사된 GABA 및 균체량 그리고 홍국이 나타내는 가장 큰 특성 중의 하나인 색도가 서로 다른 각 홍국추출물을 SHR에 경구투여하고 투여 1시간 후부터의 7시간 후까지 혈압강하효과에 미치는 영향을 측정하였다. 모든 홍국 투여군에서 혈압강하효과가 나타났으며 이 효과는 GABA나 균체량 또는 색도와 상관관계를 나타내지 않았다.