• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.169-177
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• 1993

The conversion of glutamate by glutamine synthetase Is the endergonic reaction that demands ATP as its energy source. In order to supply efficiently ATP that is demanded in the conversion of glutamate to glutamine, the ATP- generating system by acetate kinase partially purified from Escherichia coli K-12 was coupled with glutamine synthetase partially purified 5. coli K-12 Pgln6. The optinum conditions of the coupled reaction were investigated. As the result, the highest conversion of glutamate to glutamine was shown In the reaction mixture containing 100mM glutamate, 100mM NHtCl, 50M acetyl phosphate, 5mM ADP, 40M MgCl2, 300mM potassium phosphate buffer (pH 7.5), 5mM MnCl2, Under this condition, the most effective concentrations of enzyme were 70unit/ml glutamine synthetase and 99unit/ml acetate kinase. Under the optinum conditions, 98% of 100mM glutamate was converted to glutamine within 6 hours.

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.295-298
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• 1996

Under glutamine-limited condition, $2\times10^6$ (viable cells/ml) of maximum cell density and 13.5 ($\mu g$/ml) of tissue-type Plasminogen Activators (tPA) production were maintained by spike feeding fresh medium in fed-batch cultivation of human recombinant melanoma cells. It showed that tPA production was much seriously affected than cell growth according to initial glutamine concentrations. Above 3.4 (mmol/I) of glutamine concentration both cell growth and tPA production were not much affected by increasing initial glutamine concentration. Glutamine depleted situation was occurred at latter periods of batch and fed-batch cultivations below 5.4 (mmole/I) of initial glutamine concentration. It also showed that maximum glutamine consumption and ammonia evolution rates were closely related to initial glutamine concentrations. Maximum specific tPA production rate was estimated as $8.1\times19^{-6}$ ($\mu g$/cells/h) at 3.4(mmol/I) of glutamine concentration, which is higher than that from other batch and fed-batch processes.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.379-384
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• 1989

Glutamine production from glutamate was carried out using glutamine synthetase from E. coli K-12 pgln 6 and baker's yeast, which supplies ATP into the reaction system through alcohol fermentation, simultaneously. With whole cells of E. coli K-12 pgln 6 as an enzyme source of glutamine synthetase, 11.8 g/ι of glutamine produced after 18-h incubation (60％ yield based on a substrate, glutamate). Using the partially purified glutamine synthetase, 19.8 git of glutamine was produced after 5-h incubation. This amount of glutamine was correspond to 90％ yield, based on substrate, glutamate.

• KSBB Journal
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• v.11 no.3
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• pp.276-287
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• 1996

Batch suspension cultures of hybridoma cell were performed with various initial glutamine concentrations to investigate the effects of glutamine on cell growth and death, monoclonal antibody production, glucose and glutamine consumption, and the production of lactate and ammonium ion. An mathematical kinetic model was formulated to describe the kinetics of cell growth, the consumption of nutrients (glucose and glutamine), and the production of monoclonal antibody and waste metabolites (lactate and ammonium ion) based on experimental data. An equation for the specific growth rate was developed such that superimposed Monod equation in glucose and glutamine, with non-competitive type inhibition relations in ammonium ion and lactate. The inhibition constant for lactate was inversely proportional to the lactate concentration. The specific death rate was considered to be a function of glucose, glutamine, ammonium ion and lactate concentration.

• Nutritional Sciences
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• v.6 no.4
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• pp.189-194
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• 2003

Most of the ethyl alcohol consumed by humans is oxidized to acetaldehyde in the liver by the cytoplasmic alcohol dehydrogenase (ADH) system. For this ADH-catalyzed oxidation of alcohol, $NAD^+$ is required as the coenzyme and $NAD^+$becomes reduced to NADH. As the $NAD^+$becomes depleted and NADH accumulates, alcohol oxidation is reduced. For continued alcohol oxidation, the accumulated NADH must be quickly reoxidized to $NAD^+$, and it is this reoxidation of NADH to $NAD^+$that is known to be the rate-limiting step in the overall oxidation rate of alcohol The reoxidation of NADH to $NAD^+$is catalyzed by lactate dehydrogenase in the cytoplasm of hepatocytes, with pyruvate being utilized as the substrate. The pyruvate may be supplied from alanine as a result of amino acid metabolism via the urea cycle. Also, glutamine is thought to help with the supply of pyruvate indirectly, and to activate the urea cycle by producing $NH_3$. Thus, in the present study, we have examined the effects of alanine and glutamine on the alcohol oxidation rate. We utilized isolated perfused liver tissue in a system where media containing alanine and glutamine was circulated. Our results showed that when alanine (5.0mM) was added to the glucose-free infusion media, the alcohol oxidation rate was increased by 130%. Furthermore, when both glutamine and alanine were added together to the infusion media, the alcohol oxidation rate increased by as much as 190%, and the rate of urea nitrogen production increased by up to 200%. The addition of glutamine (5.0mM) alone to the infusion media did not accelerate the alcohol oxidation rate. The increases in the rates of alcohol oxidation and urea nitrogen production through the addition of alanine and glutamine indicate that these amino acids have contributed to the enhanced supply of pyruvate through the urea cycle. Based on these results, it is concluded that the dietary supplementation of alanine and glutamine could contribute to increased alcohol detoxification through the urea cycle, by enhancing the supply of pyruvate and $NAD^+$to ensure accelerated rates of alcohol oxidation.

• KSBB Journal
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• v.5 no.4
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• pp.365-371
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• 1990

To improve the growth of mouse hybridoma 2c3.1 secreting anti-Hepatitis B surface antigen monoclonal antibody (anti-HBsAg MAb), we had constructed an enriched medium and observed the effects of fetal bovine serum and serum-free supplements including human serum albumin, 'insulin and transferrin', and monoethanolamine. For further enhancement of growth, the concentrations of two major energy sources, glucose and glutamine, were strengthened with various ratios in the enriched medium. Maximum cell growth and monoclonal antibody production obtained in various ratios of glucose/glutamine with an inoculation concentration of 2$\times$105 cells/ml were 0.73$\times$106-4.62$\times$106 cells/ml and 65.1-422.6 $\mu\textrm{g}$/ml, respectively. Glutamine was round to be a major energy source and a limiting nutrient in comparison to glucose for 2c3.1 cell cultivation in enriched media with low serum.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.558-563
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• 1992

Chlorobium liimicola f. thiosulfatophilum NCIB 8327 was grown on modified Pfennig's medium using ammonium chloride. glutamine. glutamate, or dinitrogen gas as nitrogen sources. Except for the case of dinitrogen gas. the extent of gro\\1h was almost the s~me. The specific activity of glutamine synthetase in crude extracts is the highest in the cells which were grown on the medium containing glutamate. hut that of glutamate synthase is uniform for all four nitrogen sources. When the concentration of ammonium ions increases in the reaction mixture. the specific activity of glutamine synthetase in crude extract from the cells grown on glutamate decreases. hut that of glutamate dehydrogenase increases. whereas that of glutamate synthase remains unchanged. When the concentration of methionine sulfoximine increases, the activity of glutamine synthetases decreases rapidly. On the other hand. when the concentration of ammonium ions increases in the reaction mixture gradually. the activity of glutamine synthetase from the cells grown on higher concentration of ammonium ions less decreases. In the presence of light. the activity of glutamine synthetase increases. hut in the dark it decreases gradually. The production of hydrogen in intact cells depends on light. It is inhihited by adding ammonium ions. hut restores immediately hy adding methionine sulfoximine. The produclion of hydrogen in this strain can he mediated by nitrogenase only. and regulated hy glutamine synthetase.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.296-300
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• 1990

For interspecific portoplast fusion, Brevibacterium flauum lOAHR (Rifr axg his) and Corynebacterium glutamicum 11TS ($Sm-r$ trp) were induced by UV and NTG treatment. The protoplast fusion frequency between E. flavum XOAHR and C. glutamicum llTS was $3.7\times 10^{-6}$ with the lysozyme treatment (300 P $\mu g$ml) for 18 hrs. Genotypes of recombinants were analized as FMM ($Rif^r\; Sm^r$), FA (Rift $Sm^r$ arg), FH ($Rif^r\; Sm^r$ his), FT ($Rif^r\; Sm^r$ trp), FAH ($Rif^r\; Sm^r$ arg trp), FAT ($Rif^r\; Sm^r$ arg trp), and FAHT ($Rif^r\; Sm^r$ arg his trp). FAH 1 produced 12 fold of glutamate production compared to parental type, E. flauum 10AHR. In glutamine productivity, it produced 2.6 fold to parental type, C. glutamicum 11TS. Production of glutamate or glutamine by recombinants was involved in the specific activities of glutamate dehydrogenase (GDH) and glutamine synthetase (GS), respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.236-245
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• 2017

Objective: The study was to investigate the effects of alanyl-glutamine (Ala-Gln) and glutamine (Gln) supplementation on the intestinal mucosa barrier in piglets. Methods: A total of 180 barrows with initial weight $10.01{\pm}0.03kg$ were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala)], Ala-Gln diet (0.5% Ala-Gln), Gln diet (0.34% Gln and 0.21% Ala), respectively. Results: The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05), Gln supplementation increased the villi height of jejunum (p<0.05), Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05), raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1) and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05), Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05), Gln increased the number of goblet cells in duodenal epithelium (p<0.05) and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05). Conclusion: These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.506-508
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• 1986

Metabolic activity of inorganic nitrogenous compounds affects not only microbial growth but also metabolite production in fermentation technology. We have worked on the enzymes participating in ammonia assimulation of some fermentation bacteria. This paper summarizes the results on glutamine synthetase and its application in practical field. Glutamine synthetase (L-glutamate:ammonia ligase, EC. 6.3.1.2) catalyzes the formation of glutamine from glutamate and ammonia at the expense of cleavage of ATP and inorganic phosphate. The enzyme plays a dual role in nitrogen metabolism in bacteria; it is a key enzyme not only in the biosynthesis of various compounds through glutamine but also in the regulation of synthesis of some enzymes involved in the metabolism of nitrogenous compounds. The detailed works with the Eschericia coli and other enterobacterial enzymes revealed that glutamine synthetase is controlled by the following complex of mechanisms: (a) feedback inhibition by end products, (b) repression and derepression of enzyme synthesis, (c) modulation of enzyme activity in response to divalent cation and (d) covalent modification of enzyme protein by adenylylation and its cascade control. Comparative studies have also been made on the enzymes from other organisms.