• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.739-740
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• 2001

DNA microarray with a set of 37 Corynebacterium glutamicum genes encoding enzymes for primary metabolism of glycolysis, TCA cycle and lysine biosynthesis, anaplerosis etc was constructed on slide glass in triplicate. With this DNA microarray, metabolic characteristics of the lysine-producing strain was analyzed during different phase of the cultivation. The major differences in using glucose as a carbon source instead of sucrose was found in the anaplerolytic enzymes, which control the interconversion of C3 and C4 metabolites. Also, the expression profile of these major enzymes was found to be quite distinct among different phases of growth.

• BMB Reports
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• v.37 no.6
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• pp.642-647
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• 2004

The lysine residues of Bacillus licheniformis $\alpha$-amylase (BLA) were chemically modified using citraconic anhydride or succinic anhydride. Modification caused fundamental changes in the enzymes specificity, as indicated by a dramatic increase in maltosidase and a reduction in amylase activity. These changes in substrate specificity were found to coincide with a change in the cleavage pattern of the substrates and with a conversion of the native endo- form of the enzyme to a modified exo- form. Progressive increases in the productions of $\rho$-nitrophenol or glucose, when para nitrophenyl-maltoheptaoside or soluble starch, respectively, was used as substrate, were observed upon modification. The described changes were affected by the size of incorporated modified reagent: citraconic anhydride was more effective than succinic anhydride. Reasons for the observed changes are discussed and reasons for the effectivenesses of chemical modifications for tailoring enzyme specificities are suggested.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1310-1315
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• 2008

This study was to investigate the influence of pH on the antioxidant activity of melanoidins formed from glucose (Glc) and fructose (Fru) with lysine enantiomers in the Maillard reaction. Melanoidins formed from D-isomers were found to be effective antioxidants in different in vitro assays with regard to the ferrous ion chelating activity, 1, l-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activities, ferric reducing/antioxidant power (FRAP), and 2,2'-azinobis(3-ethylbenothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity. In particular, the chelating activity of these melanoidins at a pH of 7.0 was greater than those with pH of 4.0 and 10.0. The chelating activity and DPPH radical scavenging activity of the melanoidins formed from the Glc systems were higher than those of the melanoidins formed from the Fru systems. However, the FRAP and ABTS radical scavenging activity of these melanoidins were not different according to pH level, with exceptions being the Fru systems.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.526-532
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• 2016

In this study, we synthesized a mediator immobilized biocatalyst([FCA/GOx]/PEI/CNT) by surface modification using ferrocene carboxylic acid(FCA), and evaluated its performance as anode catalyst for biofuel cell. Through the application of FCA on glucose oxidase (GOx), the free amine groups on the lysine residue of GOx surface reacted with carboxylic acid of FCA and make amide bond between GOx and FCA. As the result of that, the electron transfer of catalyst was increased up to 1.91 times($0.468mA{\cdot}cm^{-2}$) than the catalyst without surface modification (GOx/PEI/CNT), and high maxium power density of $1.79mA{\cdot}cm^{-2}$ was gained.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.913-920
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• 2003

Soybean sauce fermented with soybean and wheat, has been a major condiment of Korean diets from centuries ago. Melanoidin, a brown pigment generally found in various food systems, is a final product produced in amino-carbonyl reaction during soybean sauce processing. Antioxidative activities of soybean sauce and melanoidin were investigated in vitro system using linoleic acid emulsion. Soybean sauce and glucose-lysine model melanoidin showed the stronger antioxidative effect than control by ferric thiocyanate and conjugated diene assays. In addition, DPPH radical scavenging effect of soybean sauce was higher than melanoidin, which was ascribed to soluble peptide and low molecular protein existing in soybean sauce. To ascertain antioxidative effect of dietary soybean sauce and melanoidin in vivo, the male Wister rats were fed 10% soybean sauce or 10% glucose-lysine model melanoidin with corn oil or fish oil for 5 weeks. Fatty acid compositions in liver and plasma were influenced by oil source. Therefore, EPA and DHA contents of fish oil group were higher than those of corn oil group. When the inhibitory effect of soybean sauce and melanoidin on lipid peroxidation using TBARS methods was measured, fish oil group (FC) showed higher malondialdehyde (MDA) content than corn oil group (CC). However, supplementation of soybean sauce and melanoidin to fish oil group attenuated MDA formation. In the levels of phosphatidyl choline hydroperoxide (PCOOH) in liver and plasma by CL (chemiluminescence)-HPLC method, PCOOH in FC group was significantly higher than that of CC group both in liver and plasma. Supplementation of soybean sauce to fish oil groups significantly inhibited the formation of PCOOH in plasma and liver, while melanoidin suppressed hepatic PCOOH formation. Based on these results, it can be suggested that soybean sauce possesses stronger antioxidative potential than melanoidin.

• Journal of Radiation Industry
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• v.10 no.1
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• pp.13-20
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• 2016

In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine>Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.251-261
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• 1987

This study was attempted to increase the production of L-Threonine by Brevibacterium Flavum ATCC 14067, To select the strain which produce the highest threonine, mutants ere induced by N-methyl-N'-nitro-N-nitrosoguanidine treatment. The composition of media and cultural condition for its overproduction of threonine were also studied. In a threonine producer, strain B-13(Met-) was the strain producing the highest amount of threonige among methionine, lysine and isoleucine auxotrophs. The following results were obtained. 1. The wild strain and B-13(Met-) produced threonine 1.4mg/ml and 4.86mg/ml , respectively. 2. The optimum composition of medium for producing threonine by Brevibacterium Flavum B-13 was glucose 10%, ammonium sulfate 4%, potassium phosphate monobasic 0.2%, magnesium sulfate 0.05%, biotin $200{\mu}l$, thiamine $300{\mu}l$. Addition of nicotinic acid also led to increase L-threonine production. 3. In addition of organic nutrients to the fermentation medium, peptone n'ere effective and addition of methionine $100{\mu}g/ml$ produced the highest amount of L-Threonine. Aspartic acid and homoserine were also effective when these amino acid were added to the fermentstion medium. 4. Cultural conditon on threonine production by B-16 were investigated. The optimum pH was 7.0-8.0. The highest amount of threnine was produced after 4 days of cultural period.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.161-165
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• 1982

In order to find out pertinent methods for the acceleration of browing during ginseng processing, various treatments were made or fresh ginseng (Panax Ginseng C.A. Meyer) with sugars, amino acids and inorganic nitrogenous compounds and the extent of browning was measured. Among sugars tested, maltose resulted in the greatest acceleration of browning followed in decreasing order by glucose and lactose, whereas pentoses, fructose, sucrose and raffinose had negligible effect. A marked browning occurred in ginseng treated with basic amino acids, while the extent of browning was not greatly increased when ginseng was treated with aliphatic amino acids, hydroxy amino acids, or acidic amino acids used in the experiment. Among treatments with sugar-amino acid mixture, a mixture of glucose with glutamic acid gave the greatest acceleration. The brown color intensity gradually increased with an increase in glucose concentration for up to 0.5M. inorganic nitrogenous compounds enhanced the browning in general, and the effect varied greatly with the different compounds.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.3
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• pp.33-38
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• 2021

Type 1 diabetes mellitus (T1DM) is caused by insufficient production of insulin, which is involved in carbohydrate metabolism. Type 2 diabetes mellitus (T2DM) has insulin resistance in which cells do not respond adequately to insulin. The purpose of this study was to estimate the characteristics of type 1 diabetes using streptozotocin-treated mice (STZ-mouse). The sera samples were collected from the models of hyperglycemic mouse and healthy mouse. Based on the pair-wise comparison, five metabolites were found to be noticeable: glucose, malonic acid, 3-hyroxybutyrate, methanol, and tryptophan. It was very natural glucose was upregulated in STZ-mouse. 3-hyroxybutyrate was also increased in the model. However, malonic acid, tryptophan, and methanol was downregulated in STZ-mouse. Several metabolites acetoacetate, acetone, alanine, arginine, asparagine, histidine, lysine, malate, methionine, ornithine, proline, propylene glycol, threonine, tyrosine, and urea tended to be varied in STZ-mouse while the statistical significance was not stratified for the variation. The multivariate model of PCA clearly showed the group separation between healthy control and STZ-mouse. The most significant metabolites that contributed the group separation included glucose, citrate, ascorbate, and lactate. Lactate did not show the statistical significance of change in t-test while it tends to down-regulated both in DNP and Diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.511-515
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• 2006

The chemical composition and antioxidative activities of Platycodon grandiflorum leaves and stems was investigated in order to evaluate the potential as functional food material. The moisture contents of leaves and stems were 84.31% and 75.91%, respectively. The Ca content was the highest in leaves (351.49 mg%) and stems (217.56 mg%). The major free sugar of leaves was glucose (1,729.87 mg%) However major free sugar of stems was fructose (734.91 mg%). Glutamic acid (242.91 mg%) and arginine (228.60 mg%) in leaves were major amino acids, lysine (110.08 mg%) and glutamic acid (80.40 mg%) in stems were major amino acids. Oleic acid and linoleic acid were major fatty acids in crude fat of both leaves and stems. DPPH free radical scavenging activities of fractions from leaves and stems were rising with increasing amount of fractions. Like antioxidant activity, the reducing power of fractions from leaves and stems was also dependent on concentration while butanol fraction of stems showed the highest reducing power.