• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.914-918
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• 2004

This study was carried out to analyze the metabolic flux of W. kimchii sk10 on pyruvate and ethanol as a carbon source. The sk10 grown on ethanol produced acetate under aerobic conditions rather than under anaerobic conditions. The lactate and acetate were produced on ethanol plus pyruvate by the sk10 grown under aerobic and anaerobic conditions, respectively. The resting cell of sk10 produced 99.1 mM acetate and 17.3 mM lactate under aerobic conditions and 51.1 mM acetate and 62.4 mM lactate under anaerobic conditions from ethanol plus pyruvate, respectively. This result is thought to be due to the difference in the $NADH/NAD^+$ ratio depending on the growth conditions. The 11-fold overproduction of NADH peroxidase results in a low $NADH/NAD^+$ratio under aerobic growth conditions. At the low $NADH/NAD^+$ ratio, the metabolic flux of pyruvate toward lactate has to be shifted to a flux toward acetate without NADH oxidation to $NAD^+$, and ethanol oxidation to acetate coupled to $NAD^+$ reduction to NADH has to be activated.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1452-1456
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• 2012

The anaerobic oxidation of methane (AOM) in anaerobic sewage sludge was characterized. The net methane oxidation was observed in samples amended with methane plus sulfate or with methane alone, whereas methane formation was observed in the samples without methane, indicating that methane oxidation and formation occurred simultaneously. The ratio of the net methane oxidation rate to $H_2S$ formation was 100:1, suggesting that the AOM was not closely associated with sulfate reduction in the anaerobic sludge. The net AOM was positively associated with the methane concentration and sludge dilution ratio. However, the rate of AOM was negatively correlated with organic substrate (acetate) concentration. Therefore, the production and oxidation of methane could be controlled by environmental conditions and dissolved organic compounds in the bulk solution.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.757-762
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• 2016

The group of Fe(III) oxide-reducing bacteria includes exoelectrogenic bacteria, and they possess similar properties of transferring electrons to extracellular insoluble-electron acceptors. The exoelectrogenic bacteria can use the anode in microbial fuel cells (MFCs) as the terminal electron acceptor in anaerobic acetate oxidation. In the present study, the anodic community was compared with the community using Fe(III) oxide (ferrihydrite) as the electron acceptor coupled with acetate oxidation. To precisely analyze the structures, the community was established by enrichment cultures using the same inoculum used for the MFCs. High-throughput sequencing of the 16S rRNA gene revealed considerable differences between the structure of the anodic communities and that of the Fe(III) oxide-reducing community. Geobacter species were predominantly detected (>46%) in the anodic communities. In contrast, Pseudomonas (70%) and Desulfosporosinus (16%) were predominant in the Fe(III) oxide-reducing community. These results demonstrated that Geobacter species are the most specialized among Fe(III)-reducing bacteria for electron transfer to the anode in MFCs. In addition, the present study indicates the presence of a novel lineage of bacteria in the genus Pseudomonas that highly prefers ferrihydrite as the terminal electron acceptor in acetate oxidation.

• 약학회지
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• 제46권6호
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• pp.448-451
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• 2002

Isatis indigotica is commonly used as traditional chinese medicine for antipyretic, antiviral, and detoxifying purpose in China. In order to examine whether it prevents lipid peroxidation, root of Isatis indigotica was extracted with methanol and fractionated with hexane, ethyl acetate, butanol and water. The activity was evaluated by DPPH method and lipid peroxidation in rat liver homogenate and C $u^{++}$ -induced oxidated LDL. The results showed that ethyl acetate fraction and indigo, which is known as its constituent, had significantly anti-lipid peroxidative effects.s.

• 한국식품과학회지
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• 제36권2호
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• pp.311-316
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• 2004

비타민-C를 다량 함유하고 있는 생열귀나무의 자원화를 위한 연구로서 페놀성 화합물의 함량 및 사람의 저밀도지방단백질의 산화에 대한 항산화 활성을 측정하였다. 생열귀나무 추출물의 페놀성 화합물 함량을 측정한 결과, 모든 부위에서 100g당 8.3-10.6g으로 매우 높은 양을 함유하고 있었다. 또한, 생열귀나무 추출물 및 분획물에 대한 항산화 물질의 함량을 측정 한 결과, 생열귀나무 뿌리 메탄올 추출물과 뿌리의 에틸아세테이트 및 부탄을 분획물이 285nm에서 흡수를 나타내는 페놀성 화합물을 다량 함유하고 있음을 확인하였다. TBARS에 의한 LDL산화 억제효과 측정시, 생열귀나무 뿌리의 메탄올 추출물이 가장 좋은 효과를 나타내었다. 생열귀나무 뿌리의 에틸아세테이트 및 부탄을 분회물의 경우, $30\;{\mu}g/mL$ 첨가시 85.3% 및 93.2%까지 LDL 산화를 억제함을 확인하였다. 또한 $CHCl_3$ 분획물, EtOAc 분획물, 그리고 BuOH 분획물은 $30\;{\mu}g/mL$ 분획물 첨가시 $Cu^{2+}$에 의한 LDL 산화를 8시간까지 억제함을 확인하였다. $Cu^{2+}$에 의한 apoB carbonylation과 conjugate diene형성 억제효과 측정시, EtOAc 분획물과 BuOH 분회물이 가장 탁월하게 억제함을 보여주었다. 생열귀나무는 다량의 페놀성 화합물을 함유하고 있으며 항산화 활성이 매우 탁월하므로 새로운 기능성식품 소재로의 활용이 기대되는 약용식물자원이다.

• 대한한의학방제학회지
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• 제19권2호
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• pp.109-118
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• 2011

Objectives : The Lycoris squamigera Maxim has been used traditionally for treatment of various diseases. However, the studies on the effect of Lycoris squamigera Maxim have not been carried out. In the present study, extract of Lycoris squamigera Maxim were tested for their anti-inflammatory and anti-oxidation effect. Methods : The anti-inflammatory effect of the various solvent extract was studied in lipopolysaccharide (lps)-treated mouse macrophage cells. RAW 264.7 cells were pre-incubated with Lycoris squamigera Maxim extracts for 4h and treated with $1\;{\mu}g/m{\ell}$ lps for 18h, and then the anti-inflammatory effects of extracts were determined. The anti-oxidation effect of extracts measured by DPPH method, reductive potential test, total phenolics test. Results : Extracted root's ethyl acetate layer showed a significant decrease in nitric oxide. And that layer (root's ethyl acetate extract) was showed decrease in TNF-${\alpha}$ concentration dependently. Separated from Root's ethyl acetate extract was fraction 1 has $0.1{\sim}5\;{\mu}M$ range, fraction 2 has $0.1{\sim}10\;{\mu}M$ range did not showed cytotoxicity. Anti-oxidation result as DPPH test showed the best was root ethyl acetate extract. Redusing power was made a comparison between fractions and standard. They were showed similar value. Fraction's total phenol containing result was better then standard. Conclusions : These results suggest that these extracts can be used as anti-inflammatory, anti-axidation materials.

• 약학회지
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• 제16권3호
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• pp.137-147
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• 1972

Estrone, which is obtainable from 19-hydroxycholesterol acetate through microbial oxidation, was chemically transformed to orally active estrogens, ethynylestradiol and methylestradiol. For progestin synthesis, $5{\alpha}$-bromo-619-oxidoisoandrosterone, was harvested from the culture broth(ATCC:19170), in which $5{\alpha}$-bromo-619-oxidocholestanol, acetate was added as a carbon source. Methylestrenolone, a potent orally active progestin, was synthesized from the harvested product via several reactions. Norethindrone, a popular progestin, was also prepared from 19-norandrostenedione. 19-Norandrostenedione is also available through microbial oxidation and chemical modification of $5{\alpha}$-chlor-619-oxidocholestanol, acetate.

• 한국식생활문화학회지
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• 제18권2호
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• pp.111-122
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• 2003

This studies were performed to develop a Korean traditional folk liquor namely Gangha-ju has been prepared at Bosung district in Korea, and manufacturing conditions and anti-oxidation activity and anti-microbial activity of Gangha-ju were investigated. Ethyl-alcohol 20% and 30% Gangha-ju were brewed with glutinous rice wine, distilled liquor and 6 herbs of ginger, cinnamon, etc. Chemical and physical properties of 30% Gangha-ju were acidity 0.22, pH 4.31, amino acidity 3.26, transmittance 59 and conductivity $911\;{\mu}s/m$, and 20% Gangha-ju were 0.43, 4.20, 6.26, 62 and $924\;{\mu}s/m$. Volatile flavor compounds of ethyl alcohol, acetic acid, butanol, n-amyl alcohol, iso-pentyl alcohol, ethyl acetate, butyl acetate, acetaldehyde and furfural were detected, and main aroma compounds of Gangha-ju were isopentyl alcohol and ethyl acetate. Anti-oxidation activity by DPPH method was evaluated 31.32%, and nitrite scavenging effect was 31.79%. Anti-microbial activity against several microorganisms was pronounced strong activity over a wide range of test organisms, and Leuconostoc mesenteroids and Salmonella Ttyphimurium, Staphylococcus epidermidis were found to be more sensitive to Gangha-ju than Escherichia coli and Aspergillus flavus.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.808-814
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• 2010

Activities of nanostructure HZSM-5 and Co-ZSM-5 catalysts (with different Co-loading) for catalytic conversion of ethyl acetate and toluene were studied. The catalysts were prepared by wet impregnation method and were characterized by XRD, BET, SEM, TEM and ICP-AES techniques. Catalytic studies were carried out inside a U-shaped fixed bed reactor under atmospheric pressure and different temperatures. Toluene showed lower reactivity than ethyl acetate for conversion on Co-ZSM-5 catalysts. The effect of Co loading on conversion was prominent at temperatures below $400^{\circ}C$ and $450^{\circ}C$ for ethyl acetate and toluene respectively. In a binary mixture of organic compounds, toluene and ethyl acetate showed an inhibition and promotional behaviors respectively, in which the conversion of toluene was decreased at temperatures above $350^{\circ}C$. Inhibition effect of water vapor was negligible at temperatures above $400^{\circ}C$. An artificial neural networks model was developed to predict the conversion efficiency of ethyl acetate on Co-ZSM-5 catalysts based on experimental data. Predicted results showed a good agreement with experimental results. ANN modeling predicted the order of studied variable effects on ethyl acetate conversion, which was as follows: reaction temperature (50%) > ethyl acetate inlet concentration (25.085%) > content of Co loading (24.915%).

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.80-85
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• 2005

Electrochemical control of the metabolic flux of W. kimchii sk10 on glucose and pyruvate was studied. The growing cell of W. kimchii sk10 produced 87.4 mM lactate, 69.3 mM ethanol, and 4.9mM lactate from 83.1mM glucose under oxidation condition of the anode compartment, but 98.9 mM lactate, 84.3mM ethanol, and 0.2 mM acetate were produced from 90.8 mM glucose under reduction condition of the cathode compartment for 24 h, respectively. The resting cell of W. kimchii sk10 produced 15.9 mM lactate and 15.2 mM acetate from 32.1 mM pyruvate under oxidation condition of the anode compartment, and 71.3 mM lactate and 3.8 mM acetate from 79.8mM pyruvate under reduction condition of the cathode compartment. The redox balance (NADH/$NAD^+$) of metabolites electrochemically produced from pyruvate was 1.05 and 18.76 under oxidation and reduction conditions, respectively. On the basis of these results, we suggest that the neutral red (NR) immobilized in bacterial membrane can function as an electron channel for the electron transfer between electrode and cytoplasm without dissipation of membrane potential, and that the bacterial fermentation of W. kimchii sk10 can be shifted to oxidized or reduced pathways by the electrochemical oxidation or reduction, respectively.