• Journal of Life Science
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• v.13 no.1
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• pp.90-98
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• 2003

An allium rhizobacterium Serratia plymuthica AL-1 was previously selected as a biocontrol agent of allium white rot. The chitinase from S. plymuthica AL-1 produced in medium containing colloidal chitin was purified by ammonium sulfate precipitation (40~70%), affinity adsorption, column chromatography on DEAE-sephadex A-50 and sephadex C-200 gel filtration. The enzyme was purified 10.8-fold with a yield of 7.3% from the starting culture broth. The purified chtinase gave a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis, it's molecular weight was estimated to be 55 kDa. The optimum pH and temperature of the purified enzyme were pH 5.5 and $55^{\circ}C$, respectively and it is stable up to $50^{\circ}C$ and maintains around 90% of its activity for 60min. The enzyme were activated by $Ca^{2+}$, $Mn^{2+}$ and $Mg^{2+}$ and inhibited by $Cu^{2+}$, SDS, $\rho$-CMB, MIA, respectively. The purified chitinase showed broad spectrum of antifungal activities against plant pathogenic fungi Sclerotium cepivoruin, Alternana alternnta, Colletotrichum glceosporioidrs, Phoma sp., Sclerotinia sclerotiorum, Stemphylium solani, Fusarium oxysporium f. sp. niveum but rarely inhibited Phytophthora capsici and Pythium ultimum.. The purified chitinase from S. plymuthica AL-1 caused swelling, lysis, deceleration and degradation of the hyphal tips of S. sczerotiorum causing allium white rot. It suggest that S. prymuthica AL-1 chitinase play an important part in the bifunctional chitinase / lysozyme activity.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.197-205
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• 1981

Penicillin amidase of Bacillus megaterium was recovered from the fermentation broth by adsorption on celite and immobilized by entrapping the adsorbed enzyme in acrylamide gel. The operational stability in column reactor was greatly increased by entrappment as compared with that of without entrappment. The optimum pH of the immobilized enzyme was 8.7 with broader activity profile than that of the free enzyme, while the most stable pH range appeared to be between pH 7.5 and 8.0. The optimum temperature was shifted to 5$0^{\circ}C$ from 45$^{\circ}C$ for the soluble enzyme. The values of Km and the inhibition constants for 6-APA( $K_{ia}$ ) and phenylacetic acid ( $K_{ip}$ ), were 4.55 mM, 36.5mM, and 10.5mM, respectively. No significant internal pore diffusion limitation was found since the value of effectiveness factor was 0.95. The operational half life in a column reactor at pH 8.0 was 6.8 days at 4$0^{\circ}C$ and 47 days at 3$0^{\circ}C$, whereas that of without entrappment was only 1 day and 4 days, respectively. The performance of a batch and a column reactor was also discussed with respect to the productivity. The results demonstrated that the entrappment of an adsorbed enzyme for the enhancement of the operational stability of the immobilized enzyme was useful especially when an extracellular enzyme was used.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.35-43
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• 2011

Permeable Reactive Barriers (PRB) method is an economical method that does not require any other methods to be operated once it is installed as it controls of groundwater flow in the barrier, which is inserted a reactive material on the way of pollutant. The major dominant element of PRB is a reactive material in the reactive wall, and such factors as purification efficiency and used time based on the chemical and physical features in between the reactant and pollutant. High purification efficiency can be expected when a rational design that is synthetically considered in features of packing density, operation period, and adsorption reactant of pollutant. A column test was conducted for an application test using CFW as its adsorption reactant in order to remove copper($Cu^{2+}$) in the PRB system. The CFW was used for the reactant and selected inflow speed, density and thickness of PRB as its necessary factors for design of PRB. As a result of the experiment, the removal efficiency decreased as operating time of PRB increased and the efficiency linearly increased upon the length. Therefore, it is confirmed that the thickness of reactive materials in PRB system can be designed using the proposed formula considering purification time and density of CFW.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.282-287
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• 2001

This study was carried out to investigate the difference of ginsenoside compositions in crude ginseng saponins prepared by five different methods including three new methods. Two known methods are hot methanol(MeOH) extraction/n-butanol(n-BuOH) fractionation and hot MeOH extraction/Diaion HP-20 adsorption/MeOH elution. Three new methods are hot MeOH extraction/cation AG 50W $absorption/H_2O$ elution/n-BuOH extraction, cool MeOH extraction/Diaion HP-20 adsorption/MeOH elution and direct extraction with ethyl acetate(EtOAc)/n-BuOH. Analysis of ginsenoside composition in the crude saponins by conventional HPLC/RI(Refractive Index) did not show great difference between methods except EtOAc/n-BuOH method. However, HPLC/ELSD (evaporative light scattering detector) employing gradient mobile phase afforded fine resolution of ginsenoside Rf, $Rg_1$ and $Rh_1$, and great difference of ginsenoside compositions between methods. LC/MS revealed that large amount of prosapogenins were produced during the pass through the cation exchange (AG 50W) column being strongly acidic. Six major ginsenosides such as $Rb_1,w;Rb_2,$ Rc, Rd, Re and $Rg_1$, 5 prosapogenins and one chikusetsusaponin were identified by LC/MS. A newly established HPLC method employing ODS column and gradient mobile phase of $KH_2PO_4/CH_3CN$ revealed that malonyl ginsenosides were detected only in the crude saponin obtained from cool MeOH extraction.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.23-26
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• 2004

Methyl Tertiary-Butyl Ether is one of several fuel oxygenates added to gasoline to improve fuel combustion and reduce tile resulting concentration of hydrocarbon. Thus, MTBE transfer readily to groundwater from gasoline leaking from Underground Storage Tank. Therefor, there are significant risks and costs associated with the water contamination. MTBE is far more water soluble than gasoline hydrocarbon. The purpose of the this study is to test the ability of ground tire with facultative bacteria. Bacillus brevis, to sorb MTBE. The process is consisted both batch and column experiment to determine the sorption capacity. And Biofilm is observed by SEM in the column. Finally, it is clear that ground tire represent an attractive and relatively inexpensive sorption medium for a MTBE. The authors can surmise that to determine the economic cost of ground tire utilization, tile cost to sorb a given mass of contaminant by ground tire will have to be compared to currently accepted sorption media. and Bacillus brevis strain was eliminated on MTBE, too. The biobarrier that ground tire with bacteria, has potential for use in the remediation of MTBE-contaminated environments.

• Journal of Microbiology
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• v.40 no.4
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• pp.331-334
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• 2002

The substance 0116p, which exhibits cytotoxicity against human macrophage cell line THP-1, was isolated from a mycelial extract of Streptomyces scabiei subsp. chosunensis M0137. The cytotoxic substance was purified by Diaion-HP2O adsorption, solvent extraction, Sephadex LH-20 column chromatography, and silica-gel column chromatography. The molecular formula is C$\_$19/H$\_$38/O$\_$2/ (MW301.10) based on elemental and spectrometric analysis. It was identified as nonadecanoic acid by NMR spectral data. It exhibits cytotoxic activities in various human cancer cell lines, including A549, SK-OV-3, SK-MEL-2 and HCT-15. In addition, 0116p also inhibits IL-12 production in lipopolysaccharide-activated macrophages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.296-300
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• 2003

A large equilibrium and kinetic data set for multi-component cation exchanges was obtained and tested with mass action law and surface complexation model. The systematic batch equilibrium and column experiments of cation adsorption were conducted for binary, ternary, quaternary, and quinary cation exchanges involving $ H^{+}, Li^ {+}, Na^{+}, NH$_4$^{+}, Mg^{2+} $ on a strongly acidic cation exchange resin IRN 77. The mass action law and surface complexation model were tested against both data set to investigate the consistency of ion selectivity and their predictability for competitive cation exchanges. Surface complexation model provided more accurate predictions for both equilibrium and kinetic experimental data than mass action model.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1516-1520
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• 2009

A sensitive technique for the determination of trace Co(II) in various samples after column preconcentration by adsorbing onto silica gel loaded with 1-nitroso-2-naphthol was developed. Several experimental conditions, such as pH of sample solution, the amount of silica gel loaded with 1-nitroso-2-naphthol, the flow rate for adsorption and so forth, were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) interfered with more than any other ions, but the interference by Fe(III) was completely eliminated by adjusting the amount of silica gel loaded with 1-nitroso-2-naphthol to 0.30 g. The dynamic range, the correlation coefficient ($R^2$), and the detection limit obtained by the proposed technique were 3.0-140.0 ng m$L^{-1}$, 0.9942, and 1.81 ng m$L^{-1}$, respectively. For validating the technique, the aqueous samples (tap water, reservoir water, stream water, and wastewater) and the plastic samples were used as real samples. Recovery yields of 93.0-107.0% were obtained. These measured data were not different from ICP-MS data at the 95% confidence level by F test. Based on the results of the experiment, it has been found that the proposed technique can be applied to the determination of Co(II) in various real samples.

• Analytical Science and Technology
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• v.20 no.1
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• pp.55-60
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• 2007

A sensitive technique for the determination of trace Cu(II) in various samples after the column preconcentration by adsorbing its N-benzoylphenylhydroxylamine (BPHA) onto benzophenone was developed. Several experimental conditions such as the pH of the sample solution, the amount of chelating agent, the amount of benzophenone, and the flowrate of sample solution and so forth were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) and $CN^-$ interfered with more seriously than any other ions. However, the interference by these ions could be overcome sufficiently by adjusting the added volume of 0.01M BPHA to 10 mL. The dynamic range, the correlation coefficient ($r^2$) and the detection limit obtained by this proposed technique were 5.0~120 ng/mL, 0.9974, and 2.1 ng/mL, respectively. For validating this proposed technique, the aqueous samples (stream water, reservoir water, and wastewater), the plastic sample and the diluted brass sample were used. Recovery yields of 93~102% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. This method was also validated by the rice flour CRM (normal, fortified) samples. Based on the results from the experiment, it was found that this proposed technique could be applied to the determination of Cu(II) in various real samples.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.438-443
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• 2007

This study was done to investigate perchlorate contamination in Nakdong river. The perchlorate was detected in Nakdong river and ranged from ND to $82.1{\mu}g/L$. The highest concentration was observed in Wheguan. The perchlorate concentration was decreased with the down stream of Nakdong river. Three different virgin activated carbons made of each coal(Calgon), coconut(Samchully) and wood(Picabiol) based activated carbon(AC) were tested for an adsorption performance of perchlorate in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of coal, coconut and wood based AC as 2,300 bed volumn(BV), 719 BV and 288 BV respectively. Adsorption capacity(X/M) of real, coconut and wood based AC was observed. The experimental results of adsorption capacity showed that coal based AC was highest$(768.2{\mu}g/g)$, coconut based AC was intermediate$(299{\mu}g/g)$ and wood based AC was lowest$(99.2{\mu}g/g)$. Moreover, carbon usage rates(CURs) for coal, coconut and wood based AC had been shown as 0.71 g/day, 2.16 g/day and 3.45 g/day respectively. The constant characteristic of the system, k of coal, coconut and wood based ACs were found to be 307.2, 102.5 and 94.2, respectively.