• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.250-258
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• 2019

Peniphora sp. JS17, isolated from forest old tree, produced extracellular enzymes that decolorized human hair melanin. The JS17 strain had laccase and manganese peroxidase activity while it did not has lignin peroxidase activity. Batch culture indicated that the melanin decolorization activity of JS17 strain originated from laccase. The culture conditions to maximize the production of melanin bleaching enzymes from Peniophora sp. JS17 mycelia were investigated. Among the tested media for the laccase production, minimal medium (2% glucose, 0.2% malt extract, 0.1% $KH_2PO_4$, 0.4% $MgSO_4{\cdot}7H_2O$) showed the highest activity of laccase. Then, to optimize the culture condition for the laccase activity, the influence of various carbon and nitrogen sources was investigated in minimal medium. Among various carbon and nitrogen sources, 2% xylose and 0.4% tryptone showed the highest production of laccase, respectively. The enzyme was purified using $(NH_4)_2SO_4$ precipitation and Hitrap Q sepharose column, and the purified enzyme showed two isoenzymatic bands with molecular masses of about 70 kDa by SDS-PAGE. The melanin decolorization activity was 77% and 55% within 48 h in the presence of 1-hydroxybenzotriazole (HBT) and syringaldehyde, respectively, whereas only about 9% melanin decolorized in case of no mediator.

• Journal of the Korean Chemical Society
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• v.19 no.4
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• pp.225-232
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• 1975

The elution behaviour of molybdate and tungstate through anion exchange column has been studied at the various pH. A discussion is made to evaluate the equilibrium constants of the polymerization of these acids comparing with the behaviour of chromate ion and dichromate ion. The eqailibrium constants found at $20^{\circ}$ are $K = 4{\times}10^{53} for 7MoO_4^{2-} + 8H^+ {\longleftrightarrow} Mo7O_{24}^{6- }+ 4H_2O$$ K = 3{\times}10^{54} for 6WO_4^{2-} + 7H^+ {\longleftrightarrow} HW6O_{21}^{5-} + 7H_2O$ referring to this results the conditions of separation of tungstate and molybdate are obtained. iThe quantitative separations of carbonate, molybdate and tungstate from the pregnant solution have been established by anion exchange chromatography, using the $22 cm{\times}44.27 cm^2$ column of Rexyn 201. The optimum eluents for the quantitative separation of those ions are as follows; 0.2M solution of sodium chloride at pH 8 for carbonate, the mixture of 0.5 M ammonium chloride and 0.05 M sodium sulfate at pH 5 for molybdate and 0.5 M solution of ammonium chloride at pH 10 for tungstate. Tungstate is directly recovered from the pregnant solution as a form of ammonium paratungstate, by eluting with ammonium chloride solution.

• KSBB Journal
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• v.22 no.2
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• pp.102-108
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• 2007

A sewage was treated using a vertical flow zeolite-filled reed bed. The sewage from the student dormitory of Changwon National University was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^3{\cdot}$day. The filtering height of the reed bed was 100 em and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolite: 0.5$\sim$1 mm and 1$\sim$3 mm in diameter. Annual average removal efficiency was 88 89.9%, $COD_{Cr}$ 86.1 %, $COD_{Mn}$ 81.2%, T-N 34.0%, $NH_4^+$-N 97.3% and T-P 34.6%. T-N of effluent was mostly $NO_3^-$-N and the concentration of $NO_2^-$-N in effluent was lower than 0.1 mg/L. All removal efficiencies did not show a remarkable seasonal change. The ranking of phosphorous fractions fixed to the zeolite in column test was Ca-P > Fe-P > reductant soluble Fe-P > occluded P > saloid P > AI-P at all depths of the filter. All phosphorous fractions except for AI-P reduced at deeper filter layer, while their content ratios increased at deeper filter layer. Organic matter content was the highest at the highest layer (0$\sim$5 cm from the top of the filter) and only small differences were observed at the deeper filter layer than 5 em from the top. Organic matter content increased at all depths of the filter with the operating time.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1120-1127
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• 2017

Marasmius scorodonius secretes an extracellular laccase in potato dextrose broth, and this enzyme was purified up to 206-fold using $(NH_4)_2SO_4$ precipitation and a Hi-trap Q Sepharose column. The molecular mass of the purified laccase was estimated to be ~67 kDa by SDS-PAGE. The UV/vis spectrum of the enzyme was nontypical for laccases, and metal content analysis revealed that the enzyme contains 1 mole of Fe and Zn and 2 moles of Cu per mole of protein. The optimal pH for the enzymatic activity was 3.4, 4.0, and 4.6 with 2,2'-azino-bis(3-ethylbenzothazoline-6-sulfonate) (ABTS), guaiacol, and 2,6-dimethoxy phenol as the substrate, respectively. The optimal temperature of the enzyme was $75^{\circ}C$ with ABTS as the substrate. The enzyme was stable in the presence of some metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Ni^{2+}$, $Mg^{2+}$, $Mn^{2+}$, $Ba^{2+}$, $Co^{2+}$, and $Zn^{2+}$ at a low concentration (1 mM), whereas $Fe^{2+}$ completely inhibited the enzymatic activity. The enzymatic reaction was strongly inhibited by metal chelators and thiol compounds except for EDTA. This enzyme directly decolorized Congo red, Malachite green, Crystal violet, and Methylene green dyes at various decolorization rates of 63-90%. In the presence of 1-hydroxybenzotriazole as a redox mediator, the decolorization of Reactive orange 16 and Remazol brilliant blue R was also achieved.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.106-111
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• 1994

2-iminothiolane is known to bind $NH_2$ group of lysine in the protein and deliver SH group, which can be used to label protein with $^{99m}Tc$. In this study, we looked for the best reaction condition in which 2-iminothiolane is conjugated to human polyclonal IgG and labeling condition with $^{99m}Tc$-glucoheptonate. Labeling yield was measured with TSK G4000SW column and HPLC or precipitation with 10% TCA (trichloroacetic acid) and 1% HSA. In vivo distribution was investigated with Staphylococcal abscess bearing rats. With decreasing glucoheptonate, the labeling yield decreased. Without 2-iminothiolane, $^{99m}Tc$-glucoheptonate was bound to IgG, which seemed to be direct labeling. With increasing 2-iminothiolane upto 20 times higher than IgG, the labeling yield increased, and plateau was seen with higher molar excess of 2-iminothiolane. Polymer formation was not observed. The pH for the conjugation of 2-iminothiolane and IgG was best around 6.4. $^{99m}Tc$-2-iminothiolane-IgG showed faster blood clearance, higher renal activity and lower hepatic and splenic activity than $^{99m}Tc$-DTPA-IgG. The biodistribution of $^{99m}Tc$-2-iminothiolane-IgG with higher molar excess of 2-iminothiolane was not different from that with lower molar excess. Labeling antibodies with $^{99m}Tc$ using 2-iminothiolane can afford a possible route to simple labeling and wide clinical use of the immunoscintigraphy.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.180-186
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• 1984

For the study of glucose oxidase(GOD) and catalase(CAT) coimmobilization system, the enzymes were obtained from Penicillium spp., PS-8, and the strain itself was used as an immobilizing matrix. To separate glucose oxidase and catalase after the ammonium sulfate fractionation of the culture broth, DEAF-cellulose column was used and its activity yield was 54 and 34%, respectively. Both enzymes were immobilized on the cell matrix, followed crosslinking with 2.5% glutaraldehyde for 12hr. In the determination of efficiencies of GOD and CAT of dual, mixed and soluble enzyme systems, the dual immobilized one w-as superior to those of the soluble or mixed ones. In the comparison of pH profiles, the dual and mixed types showed broader maximum pH ranges than the soluble type. Varying CAT/GOD ratio of the dual system, the higher the ratio showed the broader activity profile. In the comparison of apparent $K_m$ of GOD only and CAT/GOD=10, they were $7.1{\times}10^{-2}$ and $5.1{\times}10^{-2}M$. Their activation energies showed 3.98kcal/mole/deg for GOD only and 2.98kcal/mole/deg for CAT/GOD=10.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.113-123
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• 2012

A unit emission reduction of nitrous oxide ($N_2O$) from anthropogenic sources is equivalent to a 310-unit $CO_2$ emission reduction because the $N_2O$ has the global warming potential (GWP) of 310. This greatly promoted very active development and commercialization of catalysts to control $N_2O$ emissions from large-scale stationary sources, representatively nitric acid production plants, and numerous catalytic systems have been proposed for the $N_2O$ reduction to date and here designated to Options A to C with respect to in-duct-application scenarios. Whether or not these Options are suitable for $N_2O$ emissions control in nitric acid industries is primarily determined by positions of them being operated in nitric acid plants, which is mainly due to the difference in gas temperatures, compositions and pressures. The Option A being installed in the $NH_3$ oxidation reactor requires catalysts that have very strong thermal stability and high selectivity, while the Option B technologies are operated between the $NO_2$ absorption column and the gas expander and catalysts with medium thermal stability, good water tolerance and strong hydrothermal stability are applicable for this option. Catalysts for the Option C, that is positioned after the gas expander thereby having the lowest gas temperatures and pressure, should possess high de$N_2O$ performance and excellent water tolerance under such conditions. Consequently, each de$N_2O$ technology has different opportunities in nitric acid production plants and the best solution needs to be chosen considering the process requirements.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.161-171
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• 2003

The present study evaluated water quality variation, limiting nutrient, and sediment of a shallow eutrophic lake (Lake Ilgam) in the metropolitan area from 2000 to 2002. According to annual mean chl.a ($77.2{\pm}36.6\;{\mu}g/l) and TP ($66.6{\pm}20.5\;{\mu}g/l) concentration and trophic state index (>60), Lake llgam was in very eutrophic status. Both inorganic nitrogen ($NH_3-N$ and $NH_3-N$) and phosphorus (SRP) concentrations in the water column increased during winter and spring, but decreased during summer followed by the phytoplankton development. Evidence for phosphorus and nitrogen as being the potential limiting nutrients for phytoplankton growth was supported by the ratio of DIN/DIP (by mass) (${\sim}$835.8), TSI derivations analysis, and algal growth potential bioassay. Based on the results of TSI derivations, strong nutrient limitation by both N and P occurred from September to November when P content in sediment (114.6 mg P/kg) was relatively low compared with the summer. Sediment contained a large amount of nitrogen (TKN: 4,452${\pm}$283.0mg N/kg dry sediment). Phosphorus content in sediment (TP: 313${\pm}$155 mg P/kg) was relatively low with temporal change. P release rate (0.29${\pm}$0.02 mg $m^{-2}$ $day^{-1}$) was high under the aerobic condition at pH 9. These results indicate that the sediment could play an important role as a source of a limiting nutrient, and temporal change of P content in the sediment is closely related with water quality, especially algal biomass change in Lake llgam.

• Journal of Ginseng Research
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• v.24 no.3
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• pp.128-133
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• 2000

A high molecular (more than 10 kDa) fraction, showing mitogenic and comitogenic activities in spleen cells of mouse, was isolated from water extract of ginseng. The crude protein substance prepared by 80% (NH$_4$)$_2$SO$_4$ precipitation from this fraction was purified and isolated by DEAE Sepharose column chromatography. Among the fractions eluted, it was found that four kinds of fractions eluted with 0 to 1 M NaCl gradient were glycoproteins, which induced proliferation of spleen cells and increased NO production in macrophages. Among them, F-2 fraction, which contained 35.9% protein,49.4% neutral sugar and 12.5% uronic acid, was found to show mitogenic activity as strong as that of LPS (lipopolysaccharide) at a concentration of 100 $\mu\textrm{g}$/ml and to remarkably stimulate NO production by murine macrophages at a concentration of 500 $\mu\textrm{g}$/ml. When F-2 is deproteinized, the mitogenic activity of F-2 was decreased significantly to 70.9% as compared with that of F-2. This results suggests that the protein moiety of F-2 may play an important role in immunomodulating activity of glycoprotein from the root of Panax ginseng.

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.209-215
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• 1980

Proteases from papaya latex were partially purified by ammonium sulfate precipitation and separated into two fractions (Fraction I and II ) by carboxymethyl cellelose column chromatography. Each fraction, mixture of the two fractions, and crude extract of the papaya latex at pH 7.0 were inactivated at the range of $60{\sim}90^{\circ}C$ and thermal properties of the enzymes were investigated. In the thermal inactivation of fraction I, the enthalpy of activation was 89.5 kJ/mol; the entropy of activation, -44.0 J/mol K; the free energy of activation, 104.6 kJ/mol; z-value, $25^{\circ}C$. For fraction II, the enthalpy of activation was 96.5 kJ,/mol; the entropy of activation, -22.0 J/mol K; the free energy of activation, 104.0 kJ/mol; z-value, $23^{\circ}C$. For the mixture of fraction I and II, the enthalpy of activation was 90.9 kJ/mol; the entropy of activation, -38.8 J/mol·K; the free energy of activation, 104.2 kJ/mol; z-value, $24.6^{\circ}C$. For crude extract, the enthalpy of activation was 113.8 kJ/mol; the entropy of activation, 22.0 J/mol·K; the free energy of activation, 106.2 kJ/mol; z-value, $23.2^{\circ}C$. It was indicated that the fraction I was more heat-stable than the fraction II and this suggested that the thermal stability of the proteases in papaya latex is probably due to the fraction I.