• Applied Biological Chemistry
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• v.38 no.2
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• pp.118-122
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• 1995

Escherichia Coli ornithine transcarbamylase is the enzyme which catalyzes the L-citrulline biosynthesis from L-ornithine and carbamyl phosphate. To facilitate the purification of enzyme which will be used for many biochemical studies such as structure and function relationships and catalytic mechanisms, the cloning and expression of E. coli argI gene for ornithine transcarbamylase was conducted. argI was amplified from genomic DNA of E. coli strain of $DH5{\alpha}$, by polymerization chain reaction (PCR) method. The amplified argI gene was ligated to the prokaryotic expression vector pKK223-3 and used for transformation of E. coli TB2 which was deficient of ornithine transcarbamylase. The over-produced enzyme by the tnansformant was purified by ammonium sulfate fractionation, heat denaturation and affinity chromatography. The result of SDS denaturation gel electrophoresis for the purified enzyme showed a single band of about 38 kDa of ornithine transcarbamylase. Kinetic data for the expressed enzyme gave almost the s?????? values as those of the wild type enzyme. The $k_{cat}$, of the enzyme was $1.0{\times}10^5min^{-1}$, and $K_ms$ for ornithine and carbamyl phosphate were 0.35 mM and 0.06 mM, respectively.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.345-349
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• 2013

Physicochemical characteristics of Citrullus lanatus cv. Mudeungsan and 5 other cultivars of Citrullus lanatus were investigated. The color of watermelon (redness) was not significantly different among the cultivars. Hardness ranged from 38.76 to 52.12 force (g) among cultivars. Soluble solid content in Taeyangggul and Mudeungsan were higher than that in other cultivars. pH ranged from 5.39 to 6.02 among cultivars, and total acidity was the highest in Mudeungsan (0.147 mg/100 g). No significant difference in total carotenoid content was observed among the cultivars. Lycopene content in Mudeungsan cultivar was higher than that in other cultivars. Citrullin contents of watermelon flesh and rind in Mudeungsan and GangryeokSambok were higher than those in other cultivars. The major free sugars of watermelon were sucrose and fructose, and the predominant organic acids were succinic acid and citric acid. In conclusion, Mudeungsan cultivar had better properties as outlined above and contained soluble solids and functional components, compared to the other watermelon cultivars.

• Food Science and Preservation
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• v.13 no.3
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• pp.375-381
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• 2006

This study was carried out to analyze the nutritional component of Lepista nuda in order to estimate its nutritional and functional values. The content of moisture were $90.90{\pm}0.09%$ carbohydrate $4.34{\pm}0.07%$, crude protein $3.70{\pm}0.03%$, ash $0.55{\pm}0.04%$, and crude fat $0.47{\pm}0.01%$, respectively The reducing sugar was $636.17{\pm}7.50mg$. Total amount of free sugar was 97.32 mg, which were mainly composed of galactose (51.98 mg) and trehalose (22.48 mg). In the results of mined analysis, the content of K was the highest as $103.10{\pm}0.18mg$, followed by $56.01{\pm}0.20mg$ of Mg. The total content of hydrolyzed amino acid was 310.39 mg which consist of essential amino acids including valine (25.40 mg), leucine (22.52 mg), lysine (21.34 mg) and 198.89 mg of non-essential amino acids including glutamic acid (60.72 mg), aspartic acid (30.17 mg), and alanine (29.72 mg), as the major amino acids. free amino acids were 220.86 mg which were composed of essential amino acids (36.21 mg) inclusive of isoleucine (21.57 mg) and threonine (11.20 mg) and non-essential amino acids (184.65 mg) including glutamic acid (42.78 mg) and aspartic acid (32.44 mg) as major amino acids. Total content of amino acid derivatives was 187.85 me and that of hydroxyproline was highest as 121.50 mg.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.244-253
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• 2012

The effect of fermented Rhus verniciflua stem bark (FRVSB) extract on the microbial count, enzyme activity, concentrations of free amino acids and organic acids, and physiochemical properties of doenjang (soybean paste) was evaluated during brine fermentation. The FRVSB extract increased the total free amino acid concentration by 1.3-3.1-fold on the $42^{nd}$ day of brine fermentation. After the filtration of brine, the following microbial counts were obtained in the doenjang: bacteria, $0.3{\times}10^8-12.0{\times}10^8$ cfu/g; mold, $3.0{\times}10^4-21.0{\times}10^4$ cfu/g; yeast, $1.0{\times}10^4-2.0{\times}10^4$ cfu/g; Escherichia coli, not detected; and Bacillus cereus, $3.0{\times}10^2-25.0{\times}10^2$ cfu/g. The FRVSB extract addition enhanced the protein and starch degrading activity by 13.8-26.0% and 16.1-35.1%, respectively. The extract increased the total free amino acid content by 1.4-3.0-fold. Lactic acid, acetic acid, and pyroglutamic acid were the predominant organic acids in doenjang. Moreover, the proximate composition, pH, moisture, ash, salt, and amino nitrogen content were increased.