• The Korean Journal of Mycology
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• v.44 no.2
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• pp.87-93
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• 2016

From 182 non-pathogenic wild yeast isolates from flowers, Pichia silvicola UL6-1 and Sporobolomyces carnicolor 402-JB-1 were selected for potent ${\gamma}$-aminobutyric acid production and microbiological characteristics were investigated. Pichia silvicola UL6-1 formed ascospores and pseudomycelia. The strain was also halotolerant, growing well in 5% NaCl-containing yeast extract-peptone-dextrose (YPD) medium. Sporobolomyces carnicolor 402-JB-1 did not form ascospores or pseudomycelia and grew well on 10% glucose-yeast extract-peptone medium.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.303-309
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• 2015

${\gamma}$-Aminobutyric acid (GABA) content in fermented plant products and their main plant materials (aerial part of Acanthopanax sessiliflorus, fruit of Crataegus pinnatifida, and whole plant of Morus alba) was determined by high-performance liquid chromatography. GABA was quantified using a reverse-phase column with a gradient elution program (water:acetonitrile =90:10 to 0:100 for 40 min). UV detection was conducted at 280 nm. GABA content was measured in fermented plant products (15.07 mg/g), aerial part of A. sessiliflorus (4.49 mg/g), fruit of C. pinnatifida (10.59 mg/g), and whole plant of M. alba (2.31 mg/g). The presence of GABA in fermented plant products, including A. sessiliflorus, C. pinnatifida, and M. alba is important in industrial application for health supplements.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.652-657
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• 2015

To produce mulberry-leaf tea abundant in ${\gamma}$-aminobutyric acid (GABA), mulberry leaves were subjected to two distinct anaerobic conditions ($N_2$ and vacuum) for 12 h before the manufacturing process. Subsequently, changes in the GABA content as well as that of other components were measured. In anaerobically treated mulberry leaves, GABA content markedly increased by 436-472% compared with the control, while the glutamic acid content decreased. However, few changes were observed in the contents of the general components (moisture, carbohydrate, lipid, protein, and ash) and water-soluble solids. Free sugar, catechin, and total phenol content decreased after anaerobic treatment. However, the sensory test scores were not different between the control and anaerobically-treated samples. Consequently, tea products, manufactured post nitrogen gas or vacuum treatment of leaves after harvest, showed functional properties without sensory loss.

• Journal of Mushroom
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• v.11 no.4
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• pp.181-186
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• 2013

${\gamma}$-Aminobutyric acid(GABA) is a four carbon non-protein amino acid that has several well-known physiological functions, such as a postsynaptic inhibitory neurotransmitter in the brain and induction of hypotensive and tranquilizer effects. A lactic acid bacterium was isolated from button mushroom bed, which is showing high GABA productivity by TLC or HPLC analysis. The strain was identified as Lactobacillus hilgardii by analysis of 16S rDNA gene sequence. When the maximum production of GABA by L. hilgardii was investigated with various concentration of monosodium glutamate, the yield of GABA reached to be 53.65 mM at 1% mono sodium glutamate (MSG) in flask cultivation. A Glutamate decarboxylase (GAD) enzyme, which was known to convert MSG to GABA, was purified from a cell-free extract of L. hilgardii and the molecular weights of purified GAD was estimated to 60,000 by SDS-PAGE. The optimum pH and temperature of GAD were at pH4.6 and at $37^{\circ}C$, respectively. The GAD activity was increased by the addition of sulfate ions such as ammonium sulfate, sodium sulfate and magnesium sulfate, indicating that the increase of hydrophobic interaction causes the increase of GAD activity.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.489-496
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• 2019

A study was conducted to determine the effects of feeding ${\gamma}$-aminobutyric acid (GABA) and hydrochloric acid (HCl) on the growth performance, nutrient digestibility and fecal score in growing pigs. Ninety Duroc ${\times}$ (Landrace ${\times}$ Large Yorkshire) growing pigs with an average initial body weight (BW) of $25.51{\pm}1.63kg$ were randomly allotted to three treatment groups with 6 replications of 5 pigs per replicate pen for each treatment in a 6-week trial period. The treatments were as follows: 1) basal diet (CON); 2) basal diet with 0.05% GABA and 3) basal diet with 1% of a 10% HCl solution. The results showed that GABA supplementation significantly increased the average daily gain (ADG) (p < 0.05) compared with the control during week 4 and the overall experiment period (0 to 6 weeks). However, HCl supplementation had a numerical increase in the ADG compared with the control. The total tract digestibility of dry matter (DM) was greater in GABA group than the CON (p < 0.05). The supplementation of GABA and HCl in the diet of growing pigs had no significant effect on the fecal scores compared with the CON. Experimental results show that supplementation of 0.05% GABA in the diet of growing pigs had a positive effect on the ADG and DM digestibility in growing pigs.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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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 Mushroom
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• v.13 no.4
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• pp.334-337
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• 2015

${\gamma}$-Aminobutyric acid (GABA) is basically neurotrasmitter produced by the decarboxylation of L-glutamic acid catalyzed by glutamic acid decarboxylase (GAD), which was known to convert monosodium glutamate (MSG) to GABA. To investigate enhancement of reversion rate of GABA, the yogurt fermentation with addition of nanoparticle winter mushroom and hydroponic ginseng was used. The conversion rate was revealed to nanoparticle winter mushroom and hydroponic ginseng fermenter (88%) > winter mushroom fermenter (52%) > nanoparticle winter mushroom fermenter (44%). The results showed that nanoparticle winter mushroom and hydroponic ginseng supplemented substrates for enhancement of GABA may be used more effectively as one of potential sources of functional foods.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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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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• v.17 no.1
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• pp.49-53
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• 2002

The changes in the levels of $\gamma$ -aminobutyric acid (GABA) and some free amino acids were investigated in germinating brown rices. Ungerminated brown rices were germinated for 72 hrs by application of the following solutions: 1) distilled water, 2) 50 ppm lactic acid, 3) 5 mM glutamic acid. The GABA levels were enhanced in all germinated states of brown rices compared with ungerminated ones, highest in the germinated brown rices by 5 mM glutamic acid solution. Alanine levels were also enhanced significantly in the germinated brown rices. The levels of aspartic acid and glutamic acid were decreased significantly in all the germinated states. The levels of serine decreased during germination in the solutions of water and lactic acid were increased by the germination in the glutamic acid solution. The data show that germination of brown rices by the application of the glutamic acid solution can significantly increase the levels of GABA and can restore the serine level.

• Food Science and Preservation
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• v.13 no.3
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• pp.322-328
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• 2006

This study was designed to investigate the Quality of salted eggplants with mixed rice bran and salt during 7 days at $4^{\circ}\C$ for the quality improvement and arrangement of eggplants exported to Japan. It was carried out to analyze the changes of the color, organic acids, amino acids and minerals during salting. L and b values of eggplants were decreased, and a value of eggplants was increased during salting. Organic acids such as acetic, citric, lactic, malic, and succinic acids were analyzed from eggplants. The content of acetic and malic acid were decreased during salting, but citric and succinic acid contents were increased The major amino acids were alanine, glycine, valine and leucine. Total amino acid content of Chukyang was decreased but that of Shikibu was not changed during salting. The major free amino acid was $\gamma$-aminobutyric acid and contents of $\alpha$-aminoadipic acid and $\gamma$-aminobutyric acid were increased during salting. Sodium and potassium were major minerals of eggplants. Sodium, potassium and magnesium were increased during salting.