• Food Science and Preservation
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• v.8 no.1
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• pp.92-101
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• 2001

In order to develop the Production and application of cholesterol oxidase, a cholesterol degradation bacteria which produces a remarkable amount of extracellular cholesterol oxidase has been isolated from Korea traditional salt fermented flat fish. The isolated strain was identified as a strain of Bacil1us sp. based on its morphological, physiological characteristics and cellular fatty acid compositions. Experiments were carried out to optimize the condition of cholesterol oxidase production using Bacillus sp. SFF34. Bacillus sp. SFF34 was shown to give the maximum yield of cholesterol oxidase in the medium containing 2.0% glucose, 0.5% yeast extract, 0.02% MgSO$_4$$.$7H$_2$O, 0.025% K$_2$HPO$_4$, 0.15% NH$_4$NO$_3$ and 0.2% cholesterol. The optimum culture conditions, temperature, initial pH and agitation speed were 30$^{\circ}C$, 7.0 and 150rpm respectively. The enzyme production reached a maximum level at 24 hrs of cultivation(2.42 U/ml).

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.141-145
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• 2002

In order to clarify the neuroprotective effect of Gamibojungikki-tang (GBJIKT) water extract on cultured mouse spinal sensory neuron damaged by glucose Oxidase (GO), MTT [3-(4,5-dimethylthiazole-2-yl) -2,5-diphenyltetrazolium bromide] assay and SRB (Sulforhodamine B) assay were carried out after the cultured mouse spinal sensory neuron were preincubated with various concentrations of GBJIKT water extract for 3 hours prior to exposure of GO. Cell viability of cultured mouse spinal sensory neurons exposed to various concentrations of GO for 8 hours was decreased in a dose-dependent manner. MTT50 values were 45 mU/ml GO. Cultured mouse spinal sensory neurons in the medium containing various concentration of GO for 8 hours showed decreasing of total protein synthesis. GO was toxic on cultured spinal sensory neurons. Pretreatment at GBJIKT water extract for 3 hours following GO prevented the GO-induced neurotoxicity such as decreasing of total protein synthesis. These results suggest that GO shows toxic effect on cultured spinal sensory neurons and GBJIKT water extract is highly effective in proecting the neurotoxicity induced by GO.

• Herbal Formula Science
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• v.7 no.1
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• pp.143-151
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• 1999

To evaluate the neurotoxic effect of oxygen radicals in cultured mouse spinal dorsal root ganglion(DRG) neurons, cytotoxicity was determined by MTT assay after cultured DRG neurons were grown in the media containing various concentrations of glucose oxidase(GO). In addition, neuroprotective effect of herb extract, Epimedium Koreanum Nakai was examined by MTT assay in cultured DRG neurons. Cell viability of cultured DRG neurons was remarkably decreased by GO in dose- and time-dependent manner, and Epimedium Koreanum Nakai protected remarkably GO-induced neurotoxicity in these cultures. From the above results, it is suggested that oxygen radicals is toxic in cultured mouse DRG neurons, and herb extracts such as Epimedium Koreanum Nakai are effective in prevention of the neurotoxicity induced by oxygen radicals in cultured mouse DRG neurons.

• Molecules and Cells
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• v.22 no.1
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• pp.21-29
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• 2006

The aim of this study was to determine if hydrogen peroxide ($H_2O_2$) generated by glucose oxidase (GO) induces apoptosis or necrosis of BJAB cells and which radical is the direct mediator of cell death. We found that GO produced $H_2O_2$ continuously in low concentrations, similar to in vivo conditions, and decreased proliferation and cell viability in a dose-dependent manner. The GO-mediated cytotoxicity resulted from apoptosis, and was confirmed by monitoring the cells after H33342/Annexin V/propidium iodide staining. Decreases of mitochondrial membrane potential and intracellular glutathione level were found to be critical events in the $H_2O_2$-mediated apoptosis. Additional experiments revealed that $H_2O_2$ exerted its apoptotic action through the formation of hydroxyl radicals via the Fenton rather than the Haber-Weiss reaction. Moreover, intracellular redox-active iron, but not copper, participated in the $H_2O_2$-mediated apoptosis.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.73-83
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• 2019

The aim of this study was to investigate the effect of glucose oxidase (GOX) immobilized on magnetic chitosan nanoparticles (MCNP) on the viability of probiotic bacteria and the physico-chemical properties of drinking yogurt. Different concentrations (0, 250, and 500 mg/kg) of free and immobilized GOX were used in probiotic drinking yogurt samples. The samples were stored at $4^{\circ}C$ for 21 d. During storage, reduction of the number of probiotic bacteria in the samples with enzyme was lower than the control sample (without enzyme). The sample containing 500 mg/kg immobilized enzyme had the highest number of Bifidobacterium lactis and Lactobacillus acidophilus. The samples containing immobilized enzyme had lower acidity than other samples. Moreover, moderate proteolytic activity and enough contents of flavor compounds were observed in these samples. It can be concluded that use of immobilized GOX is economically more feasible because of improving the viability of probiotic bacteria and the physico-chemical characteristics of drinking yogurt.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.68-75
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• 1998

The overproduction and high level secretion of Glucose Oxidase (GOD) from A. niger in S. cerevisiae was carried out by cloning GOD gene. For this purpose, using two different strong promoters (ADH1 promoter, GAL10 promoter) and signal sequences (${alpha}$-MF signal sequence of S. cerevisiae and ${alpha}$-amylase signal sequence of A. oryzae) and GAL7- and GOD terminator, four expression vectors were constructed. All the expression vectors were transformed in S. cerevisiae 2805 using auxotroph method. By the flask culture, transformants of pGAL expression vector series containing GAL 10 promotor showed much higher GOD productivity than transformants of pADH expression vector series containing ADH1 promoter Transformants of pGALGO2 containing GAL10 promotor and ${alpha}$-amylase signal sequence has shown the best productivity of GOD ($GOD_{total}$: 10.3 unit/mL, $GOD_{ex}$: 8.7 unit/mL) at 115 hr. This value was three fold higher than that of pGALGO1 containing GAL 10 promotor and ${alpha}$-MF signal sequence, even if the same promotor was involved. Through the ${alpha}$-amylase signal sequence of A. oryzae, GOD was secreted much more than the case of ${alpha}$-MF signal sequence from S. cerevisiae. These results suggest that signal sequence may play a important roles in not only the secretion but also the overproduction of foreign protein. Secretion rate of GOD in pGALGO1 and pGALGO2 was 89% and 84%, respectively, Because of the overglycosylation in S. cerevisiae the molecular weight of recombinant GOD in S. cerevisiae was much larger (250 kDa) than that of nature GOD in A. niger (170 kDa).

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.874-880
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• 1993

Spectrophotometric enzymatic analysis and amperometric enzymatic analysis for the determinations of glucose and ethanol were studied utilizing glucose oxidase (GO) and alcohol oxidase (AO), respectively, which commonly consume $O_2$ and produce $H_2O_2$. For the determination of glucose, $H_2O_2$ were coupled to $K_4Fe(CN)_6$ via peroxidase producing $K_3Fe(CN)_6$ whose absorbance was measured at 418 nm or whose diffusion current was measured on the glassy carbon electrode at an applied potential of -55 mV vs. Ag/AgCl (sat. KCl) reference electrode. Amperometric analysis was 1000 times more sensitive as well as 10 times better in the linear concentration range than spectrophotometric analysis. For the determination of ethanol, AO only was used for the enzymatic analysis, since $K_3Fe(CN)_6$ was completely disappeared as soon as AO was added. Either rate of $H_2O_2$ produced was amperometrically measured at +0.900 V or rate of $O_2$ consumed was measured at -0.500 V vs. Ag/AgCl(sat. KCl) reference electrode.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.165-174
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• 1979

A purification technique of glucose oxidase was developed. Using the gluconyl-${\omega}$-aminohexyl Sepharose affinity chromatography, it was partially purified 14.6 folds with 79.7% yield. With the combination of the affinity chromatography and Sepharose 6B gel filtration, the enzyme was purified 27.2 folds from the broth with 74.1% yield. The final purified preparation showed 90.83 U of glucose oxidase activity per mg of protein and a single band by 7% polyacrylamide gel electrophoresis. The absorption spectrum and substrate specificity of the enzyme were studied and the fianal preparation showed the optimal pH between 5.6 and 6.0, the optimal temperature at $40^{\circ}C$, $8.5{\times}10^{-3}M$ of $K_m$ for D-glucose, and 3.43 kcal/mole of the activation energy.

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.137-142
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• 1988

pH decreased as the substrate mycelium developed, $\Delta$pH was 1.05-1.15, but increased after the aerial mycelium formation. The lactic acid content in culture solution showed no difference between 0.2% and 5% glucose, at which the aerial mycelium formation was repressed. The growth and development of mycelium was delayed by the lactate treatment. The activity of catalase was maximum in 24 hours after inoculation, and the wuperoxide dismutase activity showed a constant level during the developmental phases. The ascorbic acid accumulated after the aerial mycelium formation. The ascorbate oxidase isozyme of Rf 0.44 appeared, while the isozyme of Rf 0.36 desappeared during the development.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.179-183
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• 2015

In this study, we propose a catalyst structure including enzyme and metal nano rod for glucose sensing. In the catalyst structure, glucose oxidase (GOx) and gold nano rod (GNR) are alternatingly immobilized on the surface of carbon nanotube (CNT), while poly(ethyleneimine) (PEI) is inserted in between the GOx and GNR to fortify their bonding and give them opposite polarization ($[GOx/GNR]_nPEI/CNT$). To investigate the impact of $[GOx/GNR]_nPEI/CNT$ on glucose sensing, some electrochemical measurements are carried out. Initially, their optimal layer is determined by using cyclic voltammogram and as a result of that, it is proved that $[GOx/GNR/PEI]_2/CNT$ is the best layer. Its glucose sensitivity is $13.315{\mu}AmM^{-1}cm^{-2}$. When it comes to the redox reaction mechanism of flavin adenine dinucleotide (FAD) within $[GOx/GNR/PEI]_2/CNT$, (i) oxygen plays a mediator role in moving electrons and protons generated by glucose oxidation reaction to those for the reduction reaction of FAD and (ii) glucose does not affect the redox reaction of FAD. It is also recognized that the $[GOx/GNR/PEI]_3/CNT$ is limited to the surface reaction and the reaction is quasi-reversible.