• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.320-328
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• 2021

High GABA-enriched yeast extract, for various nutritionally and pharmaceutically important functional foods, was prepared using a novel isolate of Debaryomyces hansenii JBCC541. Under optimized conditions, GABA conversion rates are significantly enhanced up to 7.55 g/l by D. hansenii JBCC541, increasing their synthesis yield 40 times. The total amino acid content of the prepared yeast extract was 10733.86 mg/l (257.36 mg/g), consisting of alanine, lysine, glutamine, leucine, and valine as the primary amino acids. The GABA content was significantly enhanced up to 6790 mg/l (162.80 mg/g) in the presence of glutamic acid, with approximately 10-fold higher GABA production. Flavor amino acids were also highly enhanced, indicating that the prepared yeast extract might be useful for preparing various functional and sensuous foods. Our results were promising as a GABA-enriched yeast extract preparation tool ensuring a suitable food material level with the potential for functionally enhanced food industrial applications.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.45-51
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• 2009

$\gamma$-aminobutyric acid (GABA) is a ubiquitous nonprotein amino acid that is produced primarily by $\alpha$-decarboxylation of L-glutamic acid (Glu) catalyzed by the enzyme glutamate decarboxylase (GAD). It is well known as a neurotransmitter that regulates inhibitory neurotransmission in the mammalian central nervous system. In addition, GABA has been proved to be effective for lowering blood pressure in mammals. This paper is intended to provide basic information about GABA, including the functional and biological activity of GABA, GABA production by lactic acid bacteria, and the utilization of GABA in the production of dairy products.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1315-1320
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• 2015

To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30℃ and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

• Journal of Life Science
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• v.27 no.5
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• pp.567-574
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• 2017

This study is to isolate and identify ${\gamma}$-amino butyric acid (GABA) producing lactic acid bacteria (LAB) from Makgeolii, traditional Korean rice wine and then establish the optimal culture conditions for GABA production. Sixty four LAB from Makgeolli were isolated according to the characteristics of the shape and color of the colony grown on MRS agar plate. The GABA production of the isolated strain cultured in MRS broth contained 1% MSG (mono-sodium glutamate) were determined and evaluated by TLC and HPLC analysis. Strain B-134 was selected for highest GABA production. From the analysis of 16S rRNA and glutamate decarboxylase B (gadB) gene sequences, strain B-134 was tentatively identified as a Lactobacillus plantarum subsp. plantarum B-134. Effects of culture parameters, including glutamic acid level, culture temperature, NaCl level, and pH on GABA production were investigated for culture optimization. The optimum culture condition for GABA production by B-134 were culture temperature of $37^{\circ}C$, pH of 5.7, NaCl content of 0% (w/v) and MSG content of 3% (w/v), which produced 25 mM of GABA during cultivation time of 48 hr. From these results, strain B-134 is expected to be utilized as useful microorganisms for GABA-enriched health beneficial food.

• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.464-468
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• 2015

The production of gamma-aminobutyric acid (GABA) using GABA-producing lactic acid bacteria (LAB) has been considered to be an attractive strategy. However, some LAB may produce biogenic amines (BA), which may be of concern from the safety viewpoint. The aim of the present study was to characterize the production of GABA and BA in the soybean pastes fermented by Aspergillus oryzae (A. oryzae) FMB S46471 and GABA-producing Lactobacillus brevis (L. brevis) GABA 100. After a ripening period of 90 days, the levels of BA (putrescine, cadaverine, histamine, and tyramine) and GABA in the fermented soybean were assessed by highperformance liquid chromatography. The soybean pastes fermented by A. oryzae and L. brevis showed a range of 7,130-11,592 mg/kg for GABA, 178-305 mg/kg for tyramine, 139-163 mg/kg for putrescine, 7.4-10.8 mg/kg for histamine, and 7.1-7.9 mg/kg for cadaverine, whereas the soybean pastes fermented by A. oryzae only showed a range of 30-1,671 mg/kg for GABA, 0.8-189 mg/kg for tyramine, 1.3-85 mg/kg for putrescine, up to 3.6 mg/kg for histamine, and 0.2-2.4 mg/kg for cadaverine. The results showed that the production of GABA was accompanied by the increase in the production of BA, even though the production levels of histamine and cadaverine were very low. This is the first study to simultaneously characterize the production of BA and GABA in GABA-enriched fermented soybean pastes, and warrants further study to minimize the production of BA while optimizing the production of GABA.

• Food Science and Preservation
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• v.30 no.1
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• pp.146-154
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• 2023

To develop a multi-functional ingredient, the bioconversion of katsuobushi protein was optimized using Bacillus subtilis HA and Lactobacillus plantarum KS2020. The Dendropanax morbiferus extract (DME) culture with protease activity (102 unit/mL) was prepared by B. subtilis with 2% glucose and 1% skim milk through one day of alkaline fermentation. Katsuobushi protein was effectively hydrolyzed by the DME culture at 60℃ for 3 hours, resulting in a tyrosine content of 156.85 mg%. Subsequently, a second lactic acid fermentation was carried out with 10% monosodium glutamate (MSG) using L. plantarum KS2020 to produce higher levels of GABA. Following co-cultivation for three days, DME exhibited a pH of 8.3 (0% acidity). After seven days, the viable cell count of L. plantarum increased to 9.33 CFU/mL, but viable Bacillus cells were not detected. Taken together, a multi-functional ingredient with enriched GABA, peptides, probiotics, and umami flavor was developed through lactic acid fermentation using hydrolyzed katsuobushi protein. These results indicate that katsuobushi protein could be used as a byproduct to produce a palatable protein hydrolysate using alkaline-fermented DME culture as a proteolytic enzyme source.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.293-297
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• 2012

${\gamma}$-Aminobutyric acid-enriched sea tangle extract was obtained from the fermentation of Lactobacillus brevis BJ-20. The fermented sea tangle extract (FST) was separated into three fractions by molecular weight: FST I (greater than 10 kDa), FST II (1-10 kDa), and FST III (less than 1 kDa). The anti-inflammatory characteristics of the FST fractions were investigated by measuring the production of nitric oxide (NO) and the expression levels of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-induced mouse macrophage (RAW 264.7) cells. Both NO production and iNOS expression levels were significantly inhibited by FST treatments in a dose-dependent manner. FST III was the most effective inhibitor of processes. This demonstrates that the effect of FST on LPS-induced inflammation might be closely correlated with the inhibition of inflammatory cytokine expression.

• KSBB Journal
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• v.25 no.3
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• pp.277-282
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• 2010

This study was performed to investigate the composition of amino acids and biological properties with the ethanol extract of fruiting bodies of Pleurotus eryngii grown on the sawdust compost mix (400 g sawdust plus 200 g rice bran) supplemented with various dosages of monosodium glutamate (MSG). Amino acid composition analyses showed that arginine, glutamic acid, alanine and glycine increased as the dosage of MSG was increased, whereas histidine, serine, methionine, isoleucine, leucine and phenylalanine did not increase. $\gamma$-Aminobutyric acid (GABA) content increased significantly up to 1.18 mg/g extract when 6 g MSG was supplemented to the sawdust mix. Antioxidant activity of the extract was estimated and compared to the standard antioxidant (ascorbic acid). The antioxidant property such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity increased with the extract samples of increasing dosage of MSG. Although the extract showed low levels of nitrite scavenging activity, this activity increased up to 1.5-2.0 fold when MSG was supplemented to the sawdust mix above a dosage of 0.5 g. The results obtained from the present investigation would appear that Pleurotus eryngii grown on the MSG-enriched sawdust mix can be used more effectively as one of potential sources of functional foods.

• ALGAE
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• v.31 no.2
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• pp.175-187
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• 2016

This study evaluated the effects of γ-aminobutyric acid (GABA)-enriched fermented sea tangle (GFST), as a functional food, on brain derived neurotrophic factor (BDNF)-related muscle growth and lipolysis, in a sarcopenic obesity high-risk group. Twenty-one middle-aged women (53-63 y) participated in this randomized, double-blind, placebo controlled study. Participants ingested either 1,000 mg of GFST (n = 10) or a sucrose placebo (CON) (n = 11) everyday, for 8 weeks. Subjects were asked to abstain from any regular exercise. Fasting venous blood samples, body composition and muscular strength were measured before and after supplementation period. Collectively, we demonstrated that GFST significantly decreased total fat mass and triglyceride in body composition, as well as significantly increasing serum BDNF (p < 0.001), angiotensin converting enzyme (p < 0.001), human growth hormone and insulin-like growth factor-1 levels (p < 0.05 and p < 0.05, respectively) accompanied by increased total lean mass (p < 0.01). Furthermore, the reported improvements in total work, knee extension and flexion at 60° s⁻¹ (p < 0.05), and peak torque normalized to body weight of knee flexion at 60° s⁻¹ (p < 0.05), support an ergogenic effect of GABA associated with increased growth factor levels. The use of GFST, as a functional food ingredient, to elicit anti-obesity effects and stimulate the release of muscle-related growth factors with increasing serum BDNF levels may provide a protective intervention for age-related degeneration such as sarcopenic obesity.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.79-88
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• 2011

The sea tangle, Laminaria japonica has long been used in Korea as a folk remedy to promote health. Gamma-amino butyric acid-enriched (5.56% of dry weight) sea tangle was obtained by fermentation with Lactobacillus brevis BJ-20 (FLJ). A suppressive effect of FLJ on carbon tetrachloride-induced hepatotoxicity has been shown previously. Alcohol administration to Sprague-Dawley rats leads to hepatotoxicity, as demonstrated by heightened levels of hepatic marker enzymes as well as increases in both the number and volume of lipid droplets as fatty liver progresses. However, FLJ attenuated alcohol-induced hepatotoxicity and the accumulation of lipid droplets following ethanol administration. Additionally, FLJ increased the activities and transcript levels of major alcoholmetabolizing enzymes, such as alcohol dehydrogenase and aldehyde dehydrogenase, and reduced blood concentrations of alcohol and acetaldehyde. These data suggest that FLJ protects against alcohol-induced hepatotoxicity and that FLJ could be used as an ingredient in functional foods to ameliorate the effects of excessive alcohol consumption.