• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.244-247
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• 2020

We have expressed extracellular poly(3-hydroxybutyrate) (PHB) depolymerase of Ralstonia pickettii T1 on the Escherichia coli surface using Pseudomonas OprF protein as a fusion partner by C-terminal deletion-fusion strategy. Surface display of depolymerase was confirmed by flow cytometry, immunofluorescence microscopy and whole cell hydrolase activity. For the application, depolymerase was used as an immobilized catalyst of enantioselective hydrolysis reaction for the first time. After 48 h, (R)-methyl mandelate was completely hydrolyzed, and (S)-mandelic acid was produced with over 99% enantiomeric excess. Our findings suggest that surface displayed depolymerase on E. coli can be used as an enantioselective biocatalyst.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.259-259
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• 2006

PAU is the block copolymer consists of a small amount of a small amount of poly(${\gamma}-methyl-L-glutamate$) (PMLG) and the polyurethane. The urethane segments are hydrophobic and then strongly interact with the other hydrophobic materials such as PTFE, and the PMLG segments with the ${\alpha}-helix$ structure possess the cytocompatibility. Therefore, PAU can be easily coated onto the PTFE fiber and acts as an artificial extracellular matrix with the high cytocompatibility Results shows, the immobilization, cultured and functions of porcine hepatocytes is greatly improved.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1331-1341
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• 2015

The removal of Sr ion and Cs ion was investigated to evaluate adsorption properties by using SAN-Zeolite beads immobilized with styrene acrylonitrile (SAN). The adsorption capacities increased with the decrease of SAN/zeolite ratio (SAR) from 2.5 to 0.83. The relationship of adsorption capacity ($q_e$) and SAR was described by experimental equation such as $q_e=20.88+137.81e^{-1.96SAR}$ ($r^2=0.9980$). The adsorption kinetics of Sr ion and Cs ion with SAN-Zeolite beads were fitted well by the pseudo-second-order model. The maximum adsorption capacities of Sr ion and Cs ion calculated from Langmuir isotherm model were 66.97 mg/g and 81.97 mg/g, respectively.

• Advances in materials Research
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• v.6 no.2
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• pp.129-153
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• 2017

Platinum is a transition metal that is very resistant to corrosion. It is used as catalyst for converting methyl alcohol to formaldehyde, as catalytic converter in cars, for hydrocracking of heavy oils, in Fuel Cell devices etc. Moreover, Platinum compounds are important ingredient for cancer chemotherapy drugs. The nano forms of Platinum due to its unique physico-chemical properties that are not found in its bulk counterpart, has been found to be of great importance in electronics, optoelectronics, enzyme immobilization etc. The stability of Platinum nanoparticles has supported its use for the development of efficient and durable proton exchange membrane Fuel Cells. The present review concentrates on the use of Platinum conjugated with various metal or compounds, to fabricate nanocomposites, to enhance the efficiency of Platinum nanoparticles. The recent advances in the synthesis methods of different Platinum-based nanocomposites and their applications in Fuel Cell, sensors, bioimaging, light emitting diode, dye sensitized solar cell, hydrogen generation and in biosystems has also been discussed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.402-406
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• 2006

The physical and chemical characteristics of ALC were analyzed and showed 2.2 of specific gravity and 9.05 of pH. The results of leaching tests with standard method for soil and waste indicated heavy metals(Cu, Cd, Pb, $Cr^{6+}$) were under maximum concentration level. The anaerobic digestion sludge was attached in the surface of ALC within 90 hours. As the results of batch test, pH of the ALC and Bio-ALC were decreased from initial pH of ALC to 8.7 and 7.8 respectively Also, the concentration of heavy metals was rapidly eliminated in the solution with the batch test. The result of column experiment indicates that the removal efficiency of ALC was showed 66% of T-P, 60% of T-N, and 67% of CODcr. Also, removal efficiency of Bio-ALC was slightly higher than that of ALC in T-N (64%) and CODcr (74%).

• Journal of Environmental Science International
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• v.2 no.1
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• pp.9.2-19
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• 1993

A laboratory study was conducted to investigate the immobilization of the laboratory waste sludge, mainly from chemical oxygen demand (COD) waste, using cementitious binders. The binders were: Ordinary Portland Cement (OPC), and lime-Rice Husk Ash (RHA) cement. The economic evaluation was done for three different kinds of cementitious binders, namely, OPC, Portaind Rice Husk Ash Cement (PRHAC) which contained rice husk ash U percent by dry weight, and lime-RHA cement. The result showed that lime-RHA cement was the cheapest. The applicability of Freundlich's desorption isotherm was studied to assess the teachability of sludges. The teachability of cement mortars was found to follow the desorption isotherms. Therefore, it was concluded that based on this test, the leachate concentrations of the solidified heavy metals could be predicted, approximately by the Freundlich's isotherm desorption modeling.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.350-352
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• 2003

In this study plastic optical fibers(POFs) were considered as light-transmitting media and substrates for the potential use in photocatalytic environmental purification system. After the characteristics of POFs in terms of light transmittance and absorption were determined at the beginning, the detailed investigation was further performed through the photocatalytic degradation of trichloroethylene(TCE), iso-propanol and etc. with TiO$_2$-coated optical fiber reactor systems(POFR). It is concluded that the use of POfs is preferred to quartz optical fibers(QOFs) since the advantages such as ease of handling, lower cost, relatively reasonable light attenuation at the wavelength of near 400nm can be obtained. Various geometrical reactor shapes have been constructed and applied for the last one and half years. For the use of POF in water phase treatment, however, more detailed scientific and engineering aspects should be envisaged. This case requires a suitable mixture to obtain more stable and innocuous immobilization of photocatalyst on POF.

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.33-43
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• 2000

Mining wastes left without any proper treatment are affecting barren or arable lands where are located near and far from source through various pathway Metals are the only hazardous constituents that cannot be destroyed or altered by chemical or thermal methods and must be converted into the most insoluble and harmless form as possible, which have slower leaching rates than the original species, to prevent their reentry into the environment. Three types of chemical additives used in this study to immobilize heavy metals showed high immobilized capacity (q) and the efficiency (k) in the order of CaO, $Na_2$S.$5H_2$O, and $CaCO_3$. In addition, bentonite was considered as a good additive to remedy AM(Acid Mine Drainage) from the results of the physicochemical characteristics and immobilizing capacity. The Freundlich coefficients (n and k) from adsorption isotherm for the heavy metals adsorbed on 50g Benlonite were calculated.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.132-137
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• 2015

BEA-zeolite was modified by alkaline solution to introduce mesoporosity in the crystals and the homogeneous chiral Co(III) salen was immobilized in the mesopores. The dinuclear chiral Co(salen)-$GaCl_3$ catalyst immobilized on mesoporous BEA-zeolite showed high activity for the regioselective ring opening of terminal epoxides by carboxylic acids. Various chiral monoester derivatives could be synthesized with moderate enantioselectivity (47~69 ee%) from racemic epoxides through above reaction. When the chiral (S)-ECH was used as a reactant, it was efficiently resolved by carboxylic acid with a high enantioselectivity in the presence of heterogenized chiral salen catalyst, and the ring opened product afforded optically pure monoester epoxide (R)-GB (up to 98 ee%) through the ring closing in the basic solution by elimination of HCl. The heterogeneous catalyst could be fabricated easily, and the catalytic activity was retained for several times reuse without any further regeneration step.

• BMB Reports
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• v.36 no.3
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• pp.299-304
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• 2003

For deciphering the cyclic guanosine monophosphate (cGMP) signaling pathway, we employed chemical proteomics to identify the novel target molecules of cGMP. We used cGMP that was immobilized onto agarose beads with linkers directed at three different positions of cGMP. We performed a pull-down assay using the beads as baits on tissue lysates and identified 9 proteins by MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) mass spectrometry. Some of the identified proteins were previously known cGMP targets, including cGMP-dependent protein kinase and cGMP-stimulated phosphodiesterase. Surprisingly, some of the co-precipitated proteins were never formerly reported to associate with the cGMP signaling pathway. The competition binding assays showed that the interactions are not by nonspecific binding to either the linker or bead itself, but by specific binding to cGMP. Furthermore, we observed that the interactions are highly specific to cGMP against other nucleotides, such as cyclic adenosine monophosphate (cAMP) and 5'-GMP, which are structurally similar to cGMP. As one of the identified targets, MAPK1 was confirmed by immunoblotting with an anti-MAPK1 antibody. For further proof, we observed that the membrane-permeable cGMP (8-bromo cyclic GMP) stimulated mitogen-activated protein kinase 1 signaling in the treated cells. Our present study suggests that chemical proteomics can be a very useful and powerful technique for identifying the target proteins of small bioactive molecules.