• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.615-620
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• 2002

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidise (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized enzyme electrodes by electropolymerization added some organic solvent, such as ethanol and tetrahydrofuran (THF). The formative seeds of film growth was delayed by adding ethanol. The delay was induced by radical transfer between ethanol and pyrrole monomer. The radical transfer reactions shared the contribution of dopants between electrolyte anion and GOx polyanion. This led to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1013-1016
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• 2004

The inhibitory effect of MRPs (Maillard reaction products) on enzymatic browning of taro was investigated. The MRPs prepared by heating glycine and glucose at 9$0^{\circ}C$ for 7 hr exhibited a strong inhibitory effect on taro polyphenol oxidase (PPO). The maximum inhibitory activity of MRPs against taro PPO was detected toward (＋)-catechin, catechol, 4-methylcatechol followed by L-$\beta$-3,4-dihydroxyphenylalanine (L-DOPA) and pyragallol as a substrate. The MRPs synthesized from fructose and glucose with glycine as a amino acid significantly reduced the taro PPO activity. MRPs prepared by higher glycine or glucose concentration showed stronger inhibition against taro PPO. Increasing reaction time of the glycine and glucose promoted the inhibitory effect of MRPs against the PPO activity of taro, whereas the color formation was gradually increased.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.461-467
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• 1989

The regulation of the synthesis of alcohol-oxidase (E.C.1.1.3.13.) was investigated in the methanol-utilizing yeasts during growth on different carbon sources. For this experiment, Hansenula polymoypha CBS 4132, Hansenula polymoypha CBM 11 and Hansenula polymoypha Cooney were cultured in mineral salt medium by changing its carbon sources. The production of alcohol-oxidase was varied by the carbon sources. For exmaple, alcohol-oxidase was undetectable: in all strains submitted to the test in the medium with glucose, but its production was rapidly increased when the carbon source was changed from glucose to methanol after 30 hrs of incubation. Moreover, this enzyme was not synthesized during growth on the primary aliphatic alcohols alone (ethanol, propanol, butanol or pentanol) or on the mixed substrates (0.5% methanol + 0.5% primary aliphatic alcohols). When cells were grown on the various carbon sources (glucose, xylose, lactose, glycerol, galactose, saccharose, sorbose, lactic acid or acetic acid), the alcohol-oxidase was about one-tenth of the activity found in cells grown on methanol alone. These carbon sources together with methanol yielded far better synthesis of alcohol-oxidase than in case of carbon sources alone. Especially, the alcohol-oxidase activity of the cells grown on lactose or lactic acid together with methanol was far better or similar than that of cells grown on methanol alone. The synthetic activity of alcohol-oxidase of Hansenula polymoypha CBS 4132 was the strongest among the three strains tested in every respect.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.145-154
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• 1982

To maximize the production of glucose oxidase by Aspergillus niger KUF-04 isolated from a soil, the cultivation conditions and nutrient sources for the enzyme production were studied. The results obtained were as fellows: 1. The optimum temperature, pH of the medium, and cultivation time for the enzyme formation were found to be 28-34$^{\circ}C$, 7.0-8.0 and 40 hours, respectively. 2. The best carbon source was proved to be glucose and its most effective concentration was 15 percent. 3. Ammonium sulfate was the best nitrogen source as compared with the other inorganic and organic nitrogen sources tested. Its optimum concentration for the glucose oxidase production was 0.02 percent. 4. As mineral sources, 0.05% of Mag cesium sulfate 7-hydrate and 0.02% of Potassium phosphate, monobasic seemed to be necessary to further increase the level of the enzyme production.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.247-252
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• 1999

The oxygen electrode of a biosensor needs enzyme immobilized membrane and a dialysis membrane to measure the oxygen concentration that remains after an enzyme reacts with its substrate. Accodingly, a single-layer PVA laminated CTA/PCL membrane was developed as an oxygen biosensor electrode. The enzymes were immobilized on a cellulose triacetate/polycarprolactone membrane using the 1,1'-carbonyl diimidazole(CDI) method, and then laminated with polyvinyl alcohol, aldehyde and acid. The alcohol oxidase and PVA laminated CTA/PCL membrane was tested with various concentration of enzyme substrates using a Yellow Springs Instrument(YSI) oxygen sensor. Under 5-10mmol substrates produced $0.37{\sim}0.83{\mu}A$(r=0.995) currents, and ater 8 weeks the glucose oxidase activity remained at about 56%, while the other activities remained very low. A SEM indicated a smooth surface and tightly attached PVA on the enzyme-immobilized CTA/PCL membranes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.909-912
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• 2000

We synthesized polypyrrole (PPy) nanotubules by oxidative polymerization of the pyrrole monomer within the pores of a polycarbonate template. The electrochemical behavior was investigated using cyclic voltammetry. The redox potential was about -0.5 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for PPy film. It is considered as the backbone grows according to the pore wall. Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. By electrochemical doping of glucose oxidase (GOx) on PPy nanotubules, an enzyme electrode has been fabricated. The kinetic parameter of biochemical reaction with glucose was evaluated. The formal Michaelis constant and maximum current calculated by computer were about 11.4 mmol $dm^3$ and 170.85 A respectively. Obviously, an affinity for the substrate and current response of the PPy nanotubules enzyme electrode are rather good, comparing with that of PPy film.

• The Microorganisms and Industry
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• v.16 no.3
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• pp.15-19
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• 1990

본 연구에서는 lignin 분해시 lignin peroxidase와 glucose oxidase의 역할을 규명하기 위하여 백색부후균의 일종인 Pleurotus ostreatus를 실험 재료로 하여 glucose oxidase와 세포의 peroxidase를 분리하여 그 특성을 규명하여 이미 분리된 타 균주의 효소와 비교 분석하고, .betha.-O-4 linkage를 지닌 이합체 모델화합물에 작용시켜 그 산물을 분석함으로서 간접적이나마 두 효소의 역할및 분해기작을 추정하여 보았다.

• KSBB Journal
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• v.15 no.4
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• pp.388-392
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• 2000

An on-line glucose flow injection analysis system was developed and used for the automatic analysis and addition of glucose in the cultivationof a Saccharomyces cerevisiae in a korean paper digestion wastewater in order to increase the cell concentration. The system was composed of a ceramic sampler a sampling valve an injection valve an immobilized glucose oxidase column a debbble a flow cell with platinum electrodes a potentiostat a computer and interface system and tubing pumps. The glucose concentration of the wastewater medium was mainitained at the low concentration of $176{\pm}31 mg/L$ with the on-line FIA system and by adding glucose and $>(NH_4)_2S0_4$ the cell concentration as total cell count can be increased by 3.1times.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.417-422
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• 2003

The onions are considered to be a favorable functional source of beverage because they contain much sugar and various nutrients, and they are juicy vegetable. Recently, consumers have a new trend to take functional foods with health benefits. To meet this need, this study was the basic research to establish a manufacturing process of functional onion beverage by glucose oxidase. Glucose oxidase catalyzes reaction of glucose oxidation and makes generation of gluconic acid. Kinetics of the reaction was also investigated, and maximum glucose consumption rate $(V_{max})$ of $26.1{\times}10^{-2}\;g/L{\cdot}min$ and $K_m$ of 5.84 g/L were obtained. Optimum conditions were obtained when the glucose oxidase catalyzed reaction was carried out at temperature of $25^{\circ}C$, agitation rate of 450 rpm and aeration rate of 4 vvm in a 2.5 L jar fermentor. Finally, the enzyme reactor was 10-times scaled up and a similar glucose oxidation performance was achieved in the scaled-up reactor.

• The Korean Journal of Pharmacology
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• v.19 no.2
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• pp.35-44
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• 1983

reactive oxygen species에 의해 나타나는 reactivity에 있어서 metal ions이 관여함이 시사되고 있다. 이미 알려진 reactive oxygen species와 metal ions의 상호작용 이외에 특히 $Cu^{++}$과 $H_2O_2$가 강력한 peroxidative action을 나타낸다는 사실이 알려져 있으며 $Cu^{++}-H_2O_2$가 biological system 에서의 조직파괴에 관여할 가능성이 저자들에 의해서 효소 및 조직치 구조 단백질의 gradation 효과를 관찰함으로써 시사되었다. 본 연구는 $H_2O_2$ 혹은 $H_2O_2$를 생성하는 효소계(xanthine과 xanthine oxidase 및 glucose과 glucose oxidase)에 $Cu^{++}$을 첨가하여 $Cu^{++}-H_2O_2$에 의한 peroxidation의 효과를 collagen gelation을 통하여 확인코저 수행하였으며 다음과 같은 결과를 얻었다. 1) $Cu^{++}(20\;{\mu}M)$과 $H_2O_2$에 의하며 collagen gelation은 현저히 억제되었으며 이같은 억제효과는 양자의 농도에 비례하였다. 2) $Cu^{++}-H_2O_2$ reactivity를 확인하는 다른 방법으로 glucose oxidase system를 이용하였다. glucose oxidase$(2.5{\mu}g/ml)$ 와 glucose(0.5 mM)는 collagen gelation에 영향을 미치지 않았으나 이에 $Cu^{++}$이 존재하면 gelation이 억제되었다. 이때 억제정도는 $glucose(0.125{\sim}l.25\;mM)$와 $Cu^{++}$의 농도에 비례하였다. 3) 여러 reactive oxygen species 가운데 $Cu^{++}-H_2O_2$ reactivity를 xanthine oxidase system을 이용하여 확인하였다. (a) collagen gelation은 xanthine oxidase(30 munits/ml)와 xanthine$(0.25{\sim}2\;mM)$에 의하여 억제되었다. (b) 이때 나타나는 collagen gelation의 억제는 superoxide dismutase에 의하여 완전히 회복되었으나 catalase에 의해서는 더욱 촉진되었다. 그러나 catalase에 의한 억제효과의 촉진은 1,4-diazabicyclo(2,2,2)octane에 의하여 완전히 소실되었다. 따라서 이 xanthine oxidase system에서는 $O_2-,\;H_2O_2,\;^1O_2$이 관여함을 알 수 있었다. (c) 그러나 $Cu^{++}(10\;{\mu}M)$이 존재하였을 때 collagen gelation은 superoxie dismutase에 의해 더욱 억제되었고 catalase에 의해서는 완전히 회복되었다. xanthine oxidase계에서 얻어진 결과는 여러 reactive oxygen species가운데 $H_2O_2$가 $Cu^{++}$에 의하여 peroxidation효과를 나타냄을 알 수 있었다. 이상의 결과로 미루어 볼 때 reactive oxygen species와 metal ions과의 상호작용 가운데 $Cu^{++}-H_2O_2$는 강한 반응을 나타내는 특이한 구성요소이고 헌재 시사되고 있는 reactive oxygen species의 biological effects에 비추어 $Cu^{++}-catalyzed peroxidation$도 병적상태에서 생체에 유해한 작용을 나타내는 요소임을 시사하며 특히 염증시 조직파괴역할에 관하여 고찰하였다.