• Applied Biological Chemistry
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• v.42 no.2
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• pp.134-139
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• 1999

The characteristics of anthocyanin pigments extracted from cherry(Prunus serrulata L. var. spontanea Max. Wils.) were investigated at the various conditions, such as light, temperature, organic acid, metal ion and pH. The pigments were fairly stable under the sunlight during the 20 days storage period at room temperature. The pigments covered with the Al-foil, as well as red, blue, green and yellow films, were very stable at pH 2.5. The high thermal stability (over the 64% at $115^{\circ}C$, 30 min) of the pigments in the dark at pH 2.5 was also found. In the presence of organic acid, the hyperchromic effect of red color was greatly increased in the dark at $25^{\circ}C$. Addition of metal ion, such as $Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}\;and\;Mn^{2+}$, was contributed on the stability in color at pH 2.5 throughout 20 days storage period in the dark at $25^{\circ}C$. However, $Cu^{2+}\;and\;Fe^{3+}$ caused the rapidly degradation of pigments, and $Al^{3+}$ converted red color to blueish violet. The hyperchromic effect of the red color increased, as pH decreased. Therefore, these results indicated that cherry anthocyanin pigments might be used as the potential sources of natural red colorant for foods.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.155-160
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• 2008

Ginsenosides have been regarded as the principal components, responsible for the pharmacological and biological activities of ginseng. Absorption of major ginsenosides at the gastrointestinal tract was extremely low, when ginseng taken orally. In order to improve the absorption and bioavailability, transformation of major ginsenosides into more active and valuable minor ginsenoside is much required. In this present study, We isolated a lactic acid bacteria Leuconostoc fallax LH3 from the Korean fermented food Kimchi, which have higher ${\beta}$-glucosidase activity. Using the ethanol precipitated curd enzyme of Leuconostoc fallax LH3, we investigated the biotransformation of ginsenoside Rd at different experimental condition to increase transformation. The maximum convertion was supported at 30 $^{\circ}C$ and decreased when temperatures increased. In order to optimize the effect of pH, the curd enzyme was mixed 20 mM sodium phosphate buffer (pH 3.5 to pH 8.0). Ginsenoside Rd was almost hydrolyzed between pH 7.0 and pH 9.0, but not hydrolyzed above pH 10.0. Ginsenoside Rd was hydrolyzed after 24 hrs incubation, but whereas the ginsenoside F2 was appeared from 36 hrs, and all ginsenoside Rd was transformed to F2 after the 60 hrs incubation. Based on this study, the curd enzyme of Leuconostoc fallax LH3 transformed the ginsenoside Rd at the 30$^{\circ}C$ and the pH optimum of 7.0 to 9.0 after the 60 hrs incubation time.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.291-298
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• 2016

In this study, zwitterionic surfactants were added to liposome systems at different pH conditions to understand the effect of surfactants on liposome characteristics. For this purpose, amine oxide surfactants having different hydrocarbon chain lengths were synthesized and the structure of the resulting product was elucidated by using $^1H$ NMR, $^{13}C$ NMR, and FT-IR. In addition, the physical properties of newly synthesized surfactants such as critical micelle concentration (CMC), surface tension and isoelectric point were measured. The stability characteristics of liposome systems including average particle sizes and zeta potentials were measured by varying pH and hydrocarbon chain lengths of an amine oxide surfactant. Effects of the pH and hydrocarbon chain length of an amine oxide surfactant on fluidity of a liposome membrane were also examined by measuring the deformability and the binding degree between the surfactant and liposome.

• Journal of the Mineralogical Society of Korea
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• v.28 no.1
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• pp.39-49
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• 2015

Recently, carbon capture and storage (CCS) techniques have been globally studied. This study was conducted to use waste cement powder as an efficient raw material of mineral carbonation for $CO_2$ sequestration. Direct aqueous carbonation experiment was conducted with injecting pure $CO_2$ gas (99.9%) to a reactor containing $200m{\ell}$ reacting solution and the pulverized cement paste (W:C = 6:4) having particle size less than 0.15 mm. The effects of two additives (NaCl, $MgCl_2$) in carbonation were analyzed. The characteristics of carbonate minerals and carbonation process according to the type of additives and pH change were carefully evaluated. pH of reacting solution was gradually decreased with injecting $CO_2$ gas. $Ca^{2+}$ ion concentration in $MgCl_2$ containing solution was continuously decreased. In none $MgCl_2$ solution, however, $Ca^{2+}$ ion concentration was increased again as pH decreased. This is probably due to the dissolution of newly formed carbonate mineral in low pH solution. XRD analysis indicates that calcite is dominant carbonate mineral in none $MgCl_2$ solution whereas aragonite is dominant in $MgCl_2$ containing solution. Unstable vaterite formed in early stage of experiment was transformed to well crystallized calcite with decreasing pH in the absence of $MgCl_2$ additives. In the presence of $MgCl_2$ additives, the content of aragonite was increased with decreasing pH whereas the content of calite was decreased.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.970-977
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• 2005

The commercial $V_2O_5-WO_3/TiO_2$ catalysts which had been exposed to the off gas from incinerator for a long time were remanufactured by washing with distilled water and arid solution and reimpregnation with catalytic active components($V_2O_5-WO_3$). The catalytic properties and NOx conversion reactivity of those catalysts were examined by analysis equipment and NOx conversion experiment. Under the experimental condition used in this study, the remanufactured catalysts activated by distilled water ultra sonic cleaning, the catalytic activity was recovered in the range of $66{\sim}93%$ of that of the fresh and the maximum activity was showed when the ultra sonic cleaning time was more than 3 minutes. The remanufactured catalysts by acid solution ultra sonic cleaning, the catalytic activity was recovered in the range of $81{\sim}97%$ of that of the fresh catalyst and the maximum catalytic activity was shooed when the pH of the acid solution was 5. The remanufactured catalysts by reimpregnation with $V_2O_5$ and $WO_3$, the catalytic activity was recovered in the range of $87{\sim}100%$ of that of the fresh catalyst. Maximum catalytic activity was showed when the $V_2O_5$ was reimpregnated more than 1.0 wt %. In this case, the catalytic activity was recovered 97% of that of the fresh catalyst especially at the $150^{\circ}C$ of the experimental temperature.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.241-247
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• 2007

The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans was subcloned into the surface display vector, pCTcon (GAL1 promoter). The constructed plasmid, pCTECFTN (9.0 kb) was introduced to S. cerevisiae EBY100 cell and then east transformants were selected on the synthetic defined medium lacking uracil and on the inulin containing medium. The surface display of CFTase was confirmed by immunofluorescence microscopy and its enzymatic ability to form cycloinulooligosaccharides(cyclofructans, CFs) from inulin. The total activity of the CFTase was reached about 5.52 unit/1 by cultivation of yeast transformant on YPDG medium. The optimized conditions determined were as follows; pH, 8.0; temperature, $50^{\circ}C$ ; substrate concentration, 5%; inulin source, Jerusalem artichoke. By the reaction with inulin, CFs consisting of cycloinulohexaose (CF6), cycloinuloheptaose (CF7), and cycloinulooctaose (CF8) were produced and CF6 was the major product.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.270-274
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• 2015

We develop advanced oxidation processes for the treatment of spent electroless nickel plating solution. Apart form recovering nickel by leaching and enrichment, more emphasis is placed on rendering the waste water recyclable via oxidizing phosphite and hypophosphite into phosphate which can then be precipitated easily. $UV/H_2O_2$ process is employed and the conversion efficiency of COD and $PO_4-P$, and $H_2O_2$ consumption are analyzed. Furthermore, the $UV/H_2O_2/O_3$ process in conjunction with $O_3$ generator enables us to not only save the treatment time by 6 hours but also reduce $H_2O_2$ consumption by 30%.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.374-381
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• 2005

The production of functional foods providing health benefit is one of the fast growing fields in the food industry. Mannitol as GRAS (generally recognized as safe) is a functional food. Mannitol is about $70\%$ as sweet as sucrose and slowly and incompletely absorbed from the intestine, suppling only about one-half energy value of glucose. Commercially, the mannitol is synthesized by catalytic or electrochemical reduction of glucose. However, as strong demand for natural products increased, biological techniques have been developed for mannitol production. The object of this study was to determine the optimum conditions of mannitol fermentation by Leuconostoc mesenteroides sp. strain JFY isolated from fermented vegetables. The processes parameters such as pH, temperature, yeast extract concentration, and fructose concentration were optimized. The chosen ranges were 4.5 to 7.5 for pH, 22 to $34^{\circ}C$ for temperature, 0.05 to $2.0\%$ for yeast extract. and 5 to 350 g/L for fructose. The mineral medium used consisted of 3.0g $KH_2PO_4,\;0.01g\;FeSO_4{\cdot}H_2O,\;0.01g\;MnSO_4{\cdot}4H_2O,\;0.2g\; MgSO_4{\cdot}7H_2O,\;0.01g\;NaCl,\;and\;0.05g\;CaCl_2$ per 1 liter of deionized water. The optimum values of pH, temperature, yeast extract, and fructose concentration were obtained at about pH 6.5, temperature $28^{\circ}C$, yeast extract $0.5\%$ and fructose 30g/L. At optimum condition, the production of mannitol amounted to 31.6g/l. We hope that these findings are of particular importance for industrial application of mannitol production.

• Journal of Life Science
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• v.20 no.11
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• pp.1577-1581
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• 2010

Granulocyte colony stimulating factor (G-CSF) is a hematopoietic cytokine that stimulates bone marrow cells to proliferate and differentiate into granulocytes. G-CSF is approved and used for therapeutic purposes. The endoplasmic reticulum (ER) signal peptide of hG-CSF was replaced with silkworm-specific signal peptides to express and efficiently secrete recombinant hG-CSF by silkworm cells. Plasmids that contain cDNAs for hG-CSF and hG-CSF fused with silkworm- specific signal peptides of prophenoloxidase activating enzyme (PPAE), protein disulfide isomerase (PDI), and bombyxin (BX) were constructed. The G-CSF protein was expressed in insect cell line BM5 and was detected by western blot analysis. The cells transfected with plasmids containing rhG-CSF genes with silkworm-specific signal sequences released mature rhG-CSF protein more efficiently than the cells transfected with pG-CSF, the plasmid containing human G-CSF gene, including its own signal sequence. The production of hG-CSF reached maximal level at four days post-transfection and remained at a high level until 7 days post-transfection. These data demonstrate that the modification of the human G-CSF mimic to insect proteins synthesized in ER greatly improves the production of the protein.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.36-46
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• 1996

An endogenous phenoloxidase (EPO) from earthworm, Lumbricus rubellus, has been purified and characterized. The purified EPO using ammonium sulfate fractionation, Blue-2, Phenyl-, and Q-sepharose chromatography steps was revealed in SDS-PAGE as a single protein banri with Mr. of 59 kl)a. A native strudure of the enzyme was examined with an in situ staining of a nondenatudng-PAGE using DL-dopa as a substrate. The result showed that a single band due to the EPO activity was located siighdy above a standard polypeptide with Mr. of 210 kl)a. These fads indicate that the EPO is an oligomeric enzyme. The presence of a monophenolase activity of the purified EPO, which hydroxylates tyrosine to dopa, was confirmed by observing dopachrome accumulation at 475 nm at PH 8.0 with a typical lag phase during 60 mm. of meausrement. A series of inhibition study has been performed for the enzyme with several divalent cation chelators such as phenyithiourea (Flu), 1, lO-phenanthroline, EDTA, and EGTA. Among them, only V'flj inhibited the enzyme with 1C0.5 of 65 MM, which indicated that copper was critical for the catalysis of EPO. The enzyme was maximally active at 35'C and pH 8.0 when L-dopa to dopachrome conversion was spectrophotometricaily monitored at 475 nm. The apparent Km values of P0 for L-opa were obtained as 1.86 mM and 13.8 mM at pH 6.5 and 8.0, respectively. The catalytic efficiencies at both pH were almost identical [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92] while the Vmax at p11 8.0 was 6.6-fold higher than that at pH 6.5. This fact may indicate that pH affeds the catalysis at substrate and/or enzyme-substrate complex level rather than the enzyme itself. Taken together, the EPO was an oligomeric enzyme which did not require proteolysis for its activation. These results also indicated that the enzyme can exist, at least, in part as a latent form In vivo, which might be distinct from the prophenoloxidase activating system. Therefore, it is pertinent to consider that there must be certain regulatory molecules or phenomena in L. rubellus which make the 1,0 in a latent form in vivo before the foreign invasions.