• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.296-301
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• 2005

The effect of aqueous methanol on the catalytic properties of porcine pancreatic lipase has been investigated. The k$_{CAT}$, values for the hydrolysis of N$^{alpha}$-benzyloxycarbonyl-L­lysine p-nitrophenyl ester at 0$^{circ}$C increased in a linear manner with increasing methanol concentration. However, the K$_{M}$ values were not influenced at methanol concentrations lower than $30\%$ and then began to increase at higher concentrations in an exponential fashion. Based on product analysis, the increase in k$_{CAT}$, with increasing methanol concentration can be accounted for by nucleophilic competition of methanol for the acyl enzyme intermediate, indicating that the rate-limiting step of the porcine pancreatic lipase-catalyzed reaction is deacylation under current experimental conditions. The exponential increase in K$_{M}$ at methanol concentrations higher than $30\%$ is attributed to the hydrophobic partitioning effect on substrate binding. There was no loss of lipase activity over a 4 h period in $60\%$ methanol concentration at pH$^{circ}$ 5.5 and 0$^{circ}$C. By monitoring the intrinsic fluorescence and absorbance, no evidence for structural changes by methanol was observed.

• Journal of Microbiology
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• v.35 no.1
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• pp.30-39
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• 1997

Acinetobacter sp. strain JC1 DSM 3803, a carboxydobacterium, was found to grow methylotrophically at the expense of methanol and methlamine, but not of methane, formaldehyde, formate, dimethylamine, or trimethylamine, as the sole source of carbon and energy. The doubling times of the bacterium growing on methanol (0.5%, v/v) and methylamine (0.5%, w/v) at 3$0^{\circ}C$ and pH 6.8 were 4.8 h and 5.7 h, respectively. Cells grown on methanol, however, failed to show typical methanol dehydrogenase and oxidase activities. The cell was found to contain no c-type cytochromes. Cells grown on methanol exhibited higher catalase activity than those grown on pyruvate or glucose. The catalase present in the cells also exhibited peroxidase activity. The catalase activity, growth on methanol of the cell, and oxygen consumption by methanol-grown maldehyde dehydrogenase, formaldehyde reductase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase activities were detected from cells grown on methanol.

• Korean Journal of Microbiology
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• v.31 no.3
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• pp.179-183
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• 1993

A restricted facultatively methanol-oxidizing bacterium, Methylovorus sp. strain SS1, was isolate dfrom soil samples from Kuala Lumpur, Malaysia, through methanol-enrichment culture technique. The isolate was nonmotile Gram-negative rod and did not have complex internal membrane system. The colonies were small, pale-yellow, and raised convex with entire margin. The cell did not produce any spores and capsular materials. The cell was obligately aerobic and exhibited catalase, but no oxidase, activity. Plasmid, carotenoid pigment, and poly-.betha.-hydroxybutyric acid were not found. The guanine plus cytosine content of the DNA was 55%. The isolate was found to grow only on methanol methylamine, or glucose. Growth factors were not required. Cells growing on methanol was found to produce extracellular polysaccharides containing glucose, lactose, and fructose. Growth was optimal (t$_{d}$= 1.7) with 0.5%(v/v) methanol at 40.deg.C and pH 6.5. No Growth was observed at over 60.deg.C. Cell-free extracts of the methanol grown cells exhibited the phenazine methosulfate-linked methanol dehydrogenase activity Methanol was found to be assimilate dthrough the ribulose monophosphate pathway.y.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1985-1994
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• 2000

This research was designed to investigate the effect of initial adsorbed amount of phenol, temperature, and pH on the desorption reaction of phenol from spent activated carbon loaded with phenol. Methanol, acetone, and N,N-dimethylformamide( DMF) were used as test organic solvents. The initial adsorbed quantities of phenol investigated here were 166.1mg/g, 180.7mg/g, and 197.9mg/g. The effect of temperature was evaluated from 15 to $55^{\circ}C$ with an interval of $10^{\circ}C$, while that of pH was investigated under acidic. neutral. and alkaline conditions. The extent of phenol desorption was proportional to the strength of dipole moment such as methanol < acetone < DMF. Over 90% desorption of phenol was achieved by acetone and DMF. The quantity of des orbed phenol by the organic solvents decreases with increasing the initial adsorbed amount of phenol. DMF is affected least by the initially adsorbed amount of phenol. An increase in reaction temperature leads to higher desorption of phenol. Desorption reaction by methanol is most sensitive to the temperature. As the pH of solvents increases. the desorption rate is also increasing. At pH=12. the desorption rate of phenol by methanol increases sharply by 10%. Although methanol demonstrated the weakest desorption power. the desorption capacity of methanol would approach that of acetone and DMF by adjusting temperature and pH. Methanol may emerge as a promising solvent for removing phenol from activated carbon because of acceptable regeneration efficiency as well as relatively cheap price.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.928-935
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• 2000

This study was carried out to examine the antioxidative, antimicrobial and nitrite scavenging effects of various solvent extracts and different solvent fractions from Schizandra chinensis RUPRECHT(Omija) seed. The results were as follows; The antioxidative activities using lard, soybean oil and linoleic acid were the highest in methanol, ethanol and methanol extract from omija seed, respectively. The free radical scavenging activity using DPPH method was the strongest in acetate fraction of methanol extract from seed. The methanol extract from omija seed had the strongest antimicrobial activities to L. plantarum, B. subtilis, E. coli and P. citrinum, while ethyl acetate extract had the strongest against S. aureus and S. typhimurium. The buthanol fraction from methanol extract had the highest antimicrobial activities, followed by B. subtilis, L. plantarum, E. coli, S. aureus and S. typhimurium. The nitrite scavenging ability was pH dependent, highest at pH 1.2 and lowest at pH 6.0. The buthanol fraction of methanol extract from omija seed had more effective nitrite scavenging ability than other fractions of extracts.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.255-259
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• 2008

This study was investigated antioxidant and anticancer activity of water, methanol extract from upper and root part of Taraxacum mongolicum H. Total phenolic compound contents of methanol and water extracts from upper part were $51.95{\pm}0.18$ mg/g and $48.16{\pm}0.89$ mg/g respectively, and total flavonoid compound contents were estimated as $20.57{\pm}1.12$ mg/g in methanol extract and $6.55{\pm}1.20$ mg/g in water extract. $EC_{50}$ values for DPPH radical scavenging activity of methanol and water extract from upper part were $138.47{\pm}3.78{\mu}g/mL$ and $204.38{\pm}5.32{\mu}g/mL$, and methanol and water extracts from root part were as $512{\pm}8.11{\mu}g/mL$ in methanol extract and $1315.05{\pm}11.98{\mu}g/mL$ in water extract. Reducing power and hydroxyl radical $({\bullet}OH)$ scavenging activity estimated that methanol extract of each part were higher than water extracts. The cell viability showed that the methanol extract from upper part had a cytotoxicity in the growth of colon carcinoma cell (44.58%). Both water extract $(51.97{\pm}11.43%)$ from upper part and methanol $(53.46{\pm}19.77%)$, water $(52.79{\pm}13.53%)$ extracts from root part had quite higher cytotoxicity than that of methanol extract $(88.25{\pm}2.02%)$ from upper part. Based on the results, It was suggested that the methanol extract of Taraxacum mongolicum H. were potential materials for use as functional food and medicine.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.6-10
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• 2008

The amount of methanol crossover was measured with changing the operating condition by using a liquid methanol concentration sensor. Appropriate operating condition was discussed in terms of methanol crossover. Mechanism of methanol crossover was classified into three items which are diffusion, convection and electro-osmosis. Contribution of each mechanism to methanol crossover and the effect of operating condition were analyzed with varying methanol concentration, pressure difference between anode and cathode, current, temperature, and stoichiometry of anode fuel. Among the three mechanisms diffusion affected mostly and electro-osmosis effect was observed only under high methanol concentration.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.116-120
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• 2003

Type strain, Methylosinus trichosporium OB3b, was used to convert methane to methanol. To prevent further oxidation of methanol, NaCl and EDTA were used as inhibitors of methanol dehydrogenase. The reaction temperature was $25^{\circ}C$, and the concentrations of cell and sodium formate added to the reaction mixture were 0.6 mg dry cell wt/ml and 20 mM, respectively. During 12hr reaction, 8 mM methanol was accumulated in the reaction mixture. In this reaction $K_m$ and $V_{max}$ values were found to be 532.6 mM and 1.749 mmol/hr, respectively, and the conversion rate was approximately 37%. To increase the concentration of methanol in the medium, a repeated batch reaction was carried out. In this process, methane was injected every eight hours, and the produced methanol concentration was 18 mM.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.1-6
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• 2003

The engine performance and combustion characteristics of methanol blended fuel in a multiple-point electronic control gasoline engine were discussed on the basis of experimental investigation. The effects of methanol blending fuel on combustion in cylinder were investigated under various conditions of engine cycle and blending ratio. The results showed that the engine performance was influenced by the methanol blended ratio. The results showed that the engine performance was influenced by the methanol blending ratio and the variations of operating conditions of test engine. The increase of blended fuel brought on the improvement of emission characteristics such as THC, CO, and NOx concentration. The effect of methanol blended fuel on the fuel consumption rate and the other characteristics of performance were discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.319-322
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• 2009

This paper investigated environmental effects for passive, air-breathing, and vapor-feeding direct methanol fuel cells. In these experiments, experimental parameters are temperature($30^{\circ}C$, $40^{\circ}C$ and relative humidity(25%, 50%, 75%). From these experimental results, the water contents play a key role in terms of optimal ionic conductivity at the cathode catalyst layer. In case of pure methanol feeding, the performance is inversely proportional to the relative humidity. The water generation resulting from methanol crossover maintains ionic conductivity at the cathode. On the contrary, diluted methanol solution (50wt.%) lowers methanol crossover to the cathode. In order to increase ionic conductivity, the relatively high humidity is required to the cathode catalyst layer for the water generation. The relative humidity scales with the performance.