• KSBB Journal
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• 제17권1호
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• pp.49-53
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• 2002

GABA가 고함유된 발아현미를 생산할 수 있는 전략을 마련하고자 현미발아시 통상적인 물발아구 외에 젖산발아구, glutamic acid발아구로 나누어 발아 이전의 현미와 GABA 및 일부 유리아미노산 함량을 비교분석하였다. 5 mM glutamic acid 용액을 발아에 사용한 경우 가장 높은 GABA 함량 증진을 보여 시료 g당 및 시료 추출물 중의 단백질 mg당 증가정도가 발아하지 않은 현미에 비해 각각 8배와 12배로 나타났다. 또한 glutamic acid 발아구는 물발아나 젖산발아시 현저히 감소되던 serine의 함량을 오히려 증진시켰다. 모든 발아구에서 GABA 및 alanine 함량이 증진된 것과 는 반대로 glutamic acid와 aspartic acid 함량은 현저히 감소 하였다. 이는 발아 과정에 의해 glutamic acid는 GABA로 aspartic acid는 alanine으로 전환된 것에 기인된 것이라 여겨진다. 이상의 결과를 종합하면 현미발아시 glutamic acid액을 사용하면 기능성 물질인 GABA 함량을 현저히 증진시키며, serine의 감소를 막을 수 있어 기능성이 보강된 발아현미를 얻을 수 있을 것으로 기대된다.

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.563-567
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• 1989

알칼리성 세균으로부터 ammonium fumarate를 이용하여 글루탐산을 생성할 수 있는 균주를 분리, 동정하였으며, 글루탐산 생성에 미치는 여러가지 요인들과 생성기전에 관하여 조사하였다. 선택된 균주는 형태, 성질 등에서 Bacillus brevis와 유사하였다. 여러가지 배양조건 중에서 2% fumaric acid에 0.8% nutrient broth 를 첨가하고 암모니아수로 pH를 9로 조절한 배지에서 글루탐산 생성이 가장 좋았으며, 1% fumaric acid로부터 글루탐산으로의 전환율은 약 22%였다. 생성기전을 알아보기 위한 실험에서 whole cell을 이용하였을 때 ammonium fumarate로부터 글루탐산 생성을 볼 수 있었으며, $\alpha$-ketoglutaric acid와 aspartic acid 가 포함된 반응액에서 glutamic acid 생성과 aspartic acid 소실을 동시에 볼 수 있었다. 따라서 생성기전은 fumaric acid가 aspartic acid로 전환되고, aspartic acid와 $\alpha$-KGA가 반응하여 glutamic acid가 생성되는 것으로 추정된다.

• BMB Reports
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• 제36권3호
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• pp.319-325
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• 2003

Changes in the concentrations of $\gamma$-aminobutyric acid (GABA), soluble calcium ions, glutamic acid, and the activity of glutamate decarboxylase (GAD) were investigated in non-germinated vs. germinated brown rice. Brown rice was germinated for 72 h by applying each of the following solutions: (1) distilled water, (2) 5 mM lactic acid, (3) 50 ppm chitosan in 5 mM lactic acid, (4) 5 mM glutamic acid, and (5) 50 ppm chitosan in 5 mM glutamic acid. GABA concentrations were enhanced in all of the germinated brown rice when compared to the non-germinated brown rice. The GABA concentration was highest in the chitosan/glutamic acid that germinated brown rice at 2,011 nmol/g fresh weight, which was 13 times higher than the GABA concentration in the non-germinated brown rice at 154 nmol/g fresh weight. The concentrations of glutamic acid were significantly decreased in all of the germinated rice, regardless of the germination solution. Soluble calcium and GAD were higher in the germinated brown rice with the chitosan/glutamic acid solution when compared to the rice that was germinated in the other solutions. GAD that was partially purified from germinated brown rice was stimulated about 3.6-fold by the addition of calmodulin in the presence of calcium. These data show that the germination of brown rice in a chitosan/glutamic acid solution can significantly increase GABA synthesis activity and the concentration of GABA.

• Bulletin of the Korean Chemical Society
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• 제3권2호
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• pp.60-66
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• 1982

In relation to denaturation of proteins, thermally induced conformational change of poly(D-glutamic acid) was studied in the presence of poly(vinyl alcohol) at low pH, where poly(D-glutamic acid) undergoes a helix-to-${\beta}$ transition without any other polymer. In a dilute solution, poly(vinyl alcohol) enhanced the ${\alpah}-to-{\beta}_1$ transition of poly(D-glutamic acid) due to intermolecular interaction between the two polymers. On the other hand, this conformational change was interrupted to a large extent in a concentrated solution, due to the interpenetration of poly(vinyl alcohol) chain into poly(D-glutamic acid) chain which prevented the intramolecular association of poly(D-glutamic acid) chain. A conformational change from ${\beta}_1\;to\;{\beta}_2$ of poly(D-glutamic acid) was observed for the films obtained by casting during annealing the mixture solutions. The ${\beta}_2$ content in the cast film increased with increasing poly(vinyl alcohol) content in the mixture.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.298-303
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• 2021

Comparative genomic analysis was performed on eight species of lactic acid bacteria (LAB)-Lactococcus (L.) lactis, Lactobacillus (Lb.) plantarum, Lb. casei, Lb. brevis, Leuconostoc (Leu.) mesenteroides, Lb. fermentum, Lb. buchneri, and Lb. curvatus-to assess their glutamic acid production pathways. Glutamic acid is important for umami taste in foods. The only genes for glutamic acid production identified in the eight LAB were for conversion from glutamine in L. lactis and Leu. mesenteroides, and from glucose via citrate in L. lactis. Thus, L. lactis was considered to be potentially the best of the species for glutamic acid production. By biochemical analyses, L. lactis HY7803 was selected for glutamic acid production from among 17 L. lactis strains. Strain HY7803 produced 83.16 pmol/μl glutamic acid from glucose, and exogenous supplementation of citrate increased this to 108.42 pmol/μl. Including glutamic acid, strain HY7803 produced more of 10 free amino acids than L. lactis reference strains IL1403 and ATCC 7962 in the presence of exogenous citrate. The differences in the amino acid profiles of the strains were illuminated by principal component analysis. Our results indicate that L. lactis HY7803 may be a good starter strain for glutamic acid production.

• 미생물학회지
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• 제12권3호
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• pp.115-130
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• 1974

Searches for the nutrition requirements of three strains of Brevibacterium ammoniagenes reported in the previous paper were carried out with an aim of achieving the striking accumulation of L-glutamic acid and the large multipication of cells. It was recognized that all three strains required both biotin and thiamine, together with amino acids such as histidine or cysteine, for their good growth and extracellular L-glutamic acid accumulation. The quantity of biotin required for remarkable growth of these microorganisms was quite different from that for the maximum production of L-glutamic acid. This result, however, did not apply in the case of thiamine. It was also confirmed that, of 18 amino acids, histidine and cysteine were the msot effective organic nitrogen sources, while the most available inorganic ammonium salt resulting in a large amount of L-glutamic acid-production and considerable cell gorwth was found to be only urea. Maximum accumulation of extracellular L-glutamic acid, more than 50%(w/w) of the initial sugar content, could be obtained from fermentation in the medium containing wheat-bran extract(Brev. ammoniagenes T-1 and Brev.ammoniagenes Y-2) or rice-bran extract(Brev. ammoniagenes YR-2), which confirmed us a possibility that these bacteria might be employed for industrial fermentation of L-glutamic acid.

• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.213-218
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• 2010

In a previous paper, we showed that 5-aminosalicyl-L-aspartic acid (5-ASA-Asp) has much greater deconjugation efficiency in the cecal contents than does 5-aminosalicyl-L-glutamic acid (5-ASA-Glu). To explore a reason for ineffective deconjugation of 5-ASA-Glu, structural analysis of the conjugate was performed. Aromatic acyl-L-glutamic acid derivatives, N-benzoyl-glumatic acid (BA-Glu), N-(2-hydroxybenzoyl)-glutamic acid (SA-Glu), N-(3-aminobenzoyl)-glutamic acid (3-ABA-Glu) and N-(4-aminobenzoyl)-glutamic acid (4-ABA-Glu), were prepared and incubated in the cecal contents. The deconjugation rates were compared with that of 5-ASA-Glu. The order of the rates was BA-Glu $\approx$ 4-ABA-Glu $\approx$ 3-ABA-Glu $\gg$ SA-Glu $\approx$ 5-ASA-Glu. The deconjugation of the aromatic acyl-L-glutamic acid derivatives was carried out by enzyme(s) in the cecal contents since the deconjugation did not occur in the autoclaved cecal contents and on incubation with N-benzoyl-D-glutamic acid. Our data suggest that the 2-hydroxyl group in 5-ASA is ascribed to the poor deconjugation of 5-ASA-Glu in the cecal contents.

• 한국식품과학회지
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• 제4권2호
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• pp.112-115
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• 1972

1) 자연체에서 분리한 세균의 한 균주(No.1214)는 초산염을 자화하여 L-glutamic acid를 상당량(22g/l) 생산하였다. 2) 분리된 균주는 형태학적, 생리학적, 배양학적인 특징으로 보아 Brevibacterium flavum속으로 간주되었다.

• 한국식품영양학회지
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• 제8권4호
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• pp.275-279
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• 1995

A bacterium L-10 which produce mush of glutamic acid was Isolated from soil and identified as the genus Pserdomonas. The maximal glutamic acid production was obtained when the strain was cultured at 3$0^{\circ}C$ for 30 hrs in the optimal medium containing 5% glucose, 0.5% each of urea and yeast extract, 0.1% K2HP04, 0.02% MgSO4.7H20, 0.3% (NH, )rHP04, 0.5ug/l biotin and Initial pH 7.0, and then final glutamic acid production under the above conditions was 1.2mg/ml of cell cultures.

• 한국미생물·생명공학회지
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• 제3권3호
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• pp.147-156
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• 1975

본 실험은 Mirococcus glutamicus 균수에 의한 L-Glutamic acid 발효 생산에 있어서 Tapioca 전분의 효소당화액의 이용 가능성을 검토하였으며, 그 결과는, 20%농도의 Tapioca 전분유액에 고온성 액선균 액화효소(3000 DU/ml)를 기업 g당 30 DU 첨가하고, 85$\pm$1$^{\circ}C$, PH 6.0에서 90분간 액화한 후, Glucoamylase(4050 AU/g)을 기질 g당 15 AU 첨가하고, 55$^{\circ}C$, pH 5.0에서 36시간 가수분해시킨 당화액을 탄소원으로 사용하였을 경우가 L-Glutamic acid 생산양이 가장 양호하였다. 경화액중의 Biotin함양은 16$\mu\textrm{g}$/l로서, 과양의 Biotin농도로 인한 L-Glutamic acid 생산억제를 해결하기 위하여 첨가된 penicillin농도는 배양액ml당 10 I.U.로 배양 5시간 후 첨가하었을 경우가 가장 양호한 결과를 나타냈으며, L-Glutamic acid 생산양은 배양 60시간에서 38.5 g/l로 최대치를 나타냈다.