• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.484-490
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• 2008

Electrospun of PVP (polyvinylpyrrolidone) ultra fine fibers were fabricated using various solvents including methanol, ethanol, 2-propanol, butanol, acetone, methylene chloride, and DMF, which possess different properties such as boiling point, dielectric constant, and dipole moment. Electrospun PVP fiber was influenced by viscosity, conductivity, and surface tension of spinning solution. Therefore, the electrospun PVP fiber was successfully prepared under critical conditions of viscosity > $0.114kg/m{\cdot}s$, conductivity > 1.02 mS/m, surface tension < 30.0 mN/m. In case of an ethanol solvent system, average diameter of PVP fiber increased from 1701 nm to 5454 nm as increased the applied voltage from 10 kV to 20 kV.

• Membrane Journal
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• v.19 no.1
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• pp.83-88
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• 2009

Poly(ether block amide) (PEBA)/poly(dimethyl-siloxane) (PDMS) blend membranes (PEBA : PDMS = 5 : 2, 6 : 1 wt%) were prepared through the solution-casting and phase inversion process in order to demonstrate their superior performance in carbon dioxide separation. PDMS and PEBA (4033) were also prepared by the same method using n-butanol as a solvent. To study the gas permeation properties, the membranes were characterized with SEM and tested with carbon dioxide and nitrogen at $35^{\circ}C$ and pressure ranging from 3 to 5 atm. In conclusion, PEBA/PDMS blend membranes were shown to have selectivity for $CO_2/N_2$ separation that is 4 to 5 magnitudes greater than that of PDMS membrane at 3 atm.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.260-264
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• 1993

In order to determine the stability of ginseng components in this salt concentration when used to ginseng as additive ingredient of sauces or seasonings, we study on the content and charactristic of ginsenosides and changes in pH and color, ginseng tail and ginseng extract were treated with various concentration of NaCl solution. In this experiment, extract of ginseng tail were increased in pH as NaCl concentration were increased, but ginseng extract have not changed evidently. The both solution were decreased in color as the salt concentration were increased. Yield of n-butanol extract was decreased in 5% NaCl concentration, while it was increased in the above concentration, and ginseng extract was changed higher than ginseng tail. Ginsenosides content were increased in 5% NaCl concentration, both $ginsenosied-Rb_1$, $-Rb_2$, -Rc, -Rd of diol line and ginsenoside-Re of triol line and increased in above NaCl concentration. Especially ginsenoside-Re showed to sensitive response to the changes of the salt concentration.

• Membrane Journal
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• v.8 no.2
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• pp.77-85
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• 1998

To treat effectively EDIR (electrodeposition ion removal) wastewater in terms of CO$_{Mn}$ 1,500~2,000 ppm generated from aluminum painting process, a RO (reverse osmosis) process was designed and installed to recover and reuse the concentrated solvent sent back to the electrocodeposition tank while the permeate reused as rinse water. A RO system in which three polyamide-spiral wound modules ($102\Phi \times 1,016L$ mm) connnected in series had been running to treat 20 m$^3$ in waste volume in 3 days batch operation at the condition of system recovery of 30 %, applied pressure 11.5 $kg_f/cm^2$ and room temperature. During 42 hours continuous operation leading to 5-fold decrease in waste volume, nearly constant permeation flux of 390 l/m$^2$-hr was maintained and the permeate with average CO$_{Mn}$, 300 ppm was obtained which could be used for washing the remaining paint solution in ion-exchange tower instead of demineralized water. Also COD$_{Mn}$ rejection as a function of running time was observed to be in the range of 78~87 % and the observed solvent rejections for ethyl cellusolve, buthyl cellusolve and n-butanol were 79 %, 87 % and 70 %, respectively.

• Resources Recycling
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• v.24 no.3
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• pp.59-65
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• 2015

Recycling of vulcanized rubber products is a serious problem in the world. A quantity of generated waste tires becomes much more and more because of increasing demands on automobiles, resulted in the cause of serious secondary pollution by sulfur component that is crosslinked to incineration or landfill. In addition, crosslinked surfur is used to interfere with the binding of the raw material rubber. In this study, we analyzed the degree of devulcanization by the chemical devulcanization. Devulcanization ratio of the samples were systematically analysed by variables such as time and temperature. In addition, the effect of swelling method as a pre-treatment process was also measured. A rubber specimen was deepened in a organic 2-buthanol solutions during various times of 1 ~ 5 hrs at 100, 150, $200^{\circ}C$ respectively, then to calculate the crosslink density and the number average molecular weight by using a parallel expansion process, which showed devulcanization degree of analyzed samples quantitatively. Also, the mechanical properties were measured with the samples prepared by using a hot press.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1393-1400
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• 2021

Acetone-butanol-ethanol (ABE) fermentation by the anaerobic bacterium Clostridium acetobutylicum has been considered a promising process of industrial biofuel production. Phosphotransbutyrylase (phosphate butyryltransferase, PTB) plays a crucial role in butyrate metabolism by catalyzing the reversible conversion of butyryl-CoA into butyryl phosphate. Here, we report the crystal structure of PTB from the Clostridial host for ABE fermentation, C. acetobutylicum, (CaPTB) at a 2.9 Å resolution. The overall structure of the CaPTB monomer is quite similar to those of other acyltransferases, with some regional structural differences. The monomeric structure of CaPTB consists of two distinct domains, the N- and C-terminal domains. The active site cleft was formed at the interface between the two domains. Interestingly, the crystal structure of CaPTB contained eight molecules per asymmetric unit, forming an octamer, and the size-exclusion chromatography experiment also suggested that the enzyme exists as an octamer in solution. The structural analysis of CaPTB identifies the substrate binding mode of the enzyme and comparisons with other acyltransferase structures lead us to speculate that the enzyme undergoes a conformational change upon binding of its substrate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1821-1828
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• 2013

This study was conducted to investigate the physicochemical and microbial properties of Makgeolli supplemented with kiwifruit (Actinidia deliciosa). Four hundred grams of kiwifruit were added to 3.1 L of distilled water, followed by 2.0 kg of rice, 40.0 g of Nuruk, and 14.0 g of yeast. The mixed rice solution was then fermented at $28^{\circ}C$ for 6 days to prepare the kiwifruit Makgeolli. The pH values of the kiwifruit Makgeolli decreased from 5.31 to 4.37, but the total acidity values increased from 0.05 to 0.34% during fermentation. The total viable cells ($3.18{\times}10^7$ and $2.88{\times}10^7$, respectively), lactic acid bacteria ($1.51{\times}10^6$ and $1.50{\times}10^6$, respectively), and yeast counts ($1.96{\times}10^7$ and $1.90{\times}10^7$, respectively) of the kiwifruit Makgeolli and control were similar throughout the fermentation process. Glucose was the major free sugar in the control and kiwifruit Makgeolli and significantly decreased during fermentation. Succinic acid was the highest organic acid in both the control (24.6 mg/mL) and kiwifruit Makgeolli (26.3 mg/mL). In a volatile compound analysis, 3-methyl-1-butanol, 2-methyl-1-propanol and ethyl acetate were the major volatile compounds in the kiwifruit Makgeolli.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.19-26
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• 1996

A phospholipase C (PLC) inhibitor (MT267-2B) was isolated from the culture broth of actinomycetes isolate MT2617-2 by the extraction with n-butanol and column chromatographic techniques. The molecular weight of the inhibitor was 1057, by the spectroscopic analyses of IR, $^{13}C$-and $^{1}H$-NMR and ESI-MS. The chemical structure of MT2617-2B was found to be a macrolide compound consisted of a hemiketal ring, polyhydroxyl and polymethyl groups, which had a malonate and guanidine group as its side chain. MT2617-2B produced its two isomers having the same molecular weight by standing in methanol solution at room temperature. Therefore, MT2617-2B was identified as copiamycin and niphithricin A, macrolide antibiotics. The values of $IC_{50}$ against PLC-${\gamma}$1 and PLC-${\beta}$1 were 25 and 50${\mu}$g/ml, respectively. MT2617-2B had antimicrobial activities against Staphylococcus aureus and Candida albicans, but not against Escherichia coli.

• Research in Plant Disease
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• v.21 no.2
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• pp.50-57
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• 2015

Control of nematode has become difficult owing to the restricted use of effective soil fumigant, methyl bromide, and other non-fumigant nematicides. Therefore, it is urgently necessary to develop microbial nematicide to replace chemical nematicides. In this study, the 50% aqueous methanol extraction solution of fermentation broths of 2,700 actinomycete strains were tested for their nematicidal activity against second stage of juveniles (J2s) of Meloidogyne incognita. As the results, only the 50% aqueous methanol extraction solution of AN110065, at 20% equivalent to 10% fermentation broth, showed strong nematicidal activity with 78.9% of mortality 24 h after treatment and 94.1% of mortality at 72 h. The 16S rRNA gene sequencing showed that the strain sequence was 99.78% identical to Streptomyces netropsis. The extract of S. netropsis AN110065 fermentation broth was successively partitioned with ethyl acetate and butanol and then the ethyl acetate, butanol and water layers were investigated for their nematicidal activity against the M. incognita. At $1000{\mu}g/ml$, ethyl acetate layer showed the strongest activity of 83.5% of juvenile mortality 72 h after treatment. The pot experiment using the fermentation broth of AN110065 on tomato plant against M. incognita displayed that it evidently suppressed gall formation at a 10-fold diluent treatment. The tomato plants treated with the fermentation broth of S. netropsis AN110065 did not show any phytotoxicity. The results suggest that S. netropsis AN110065 has a potential to serve as microbial nematicide in organic agriculture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.223-228
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• 2011

Korean traditional rice wine, Makgeolli, has been widely consumed with increasing popularity in Korea. Also, there has been an increase in the varieties of Makgeolli for the younger generation. In this study, we examined the physicochemical and microbial properties of Makgeolli supplemented with cucumber during fermentation. Four hundred grams of cucumbers (20% of the total amount of rice) were grinded and added to the rice solution (2 kg rice and 3.12 L distilled water) along with the Nuruk (40 g) and yeast (14 g). After mixing the solution, it was fermented for six days in a water bath ($28^{\circ}C$). During the fermentation, the pH value of the cucumber Makgeolli fell from 5.88 to 3.94 on day-1, and steadily increased to a pH value of 4.48 by day-6. The total acidity of the cucumber Makgeolli sharply increased from 0.02 to 0.20% on day-1, and then slowly increased thereafter to 0.28% by day-6. After the 6-day fermentation, the L values of the control and the cucumber Makgeolli were similar. The total viable cell, lactic acid bacteria and yeast count of the control and the cucumber Makgeolli increased considerably after the 6-day fermentation process. Free sugar analysis showed that glucose contents decreased with increasing fermentation periods. The succinic acid content was the highest among all the organic acids. Thirty-nine volatile compounds were observed on the final day of fermentation in the cucumber Makgeolli.