• BMB Reports
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• v.41 no.3
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• pp.223-229
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• 2008

Reactive oxygen species (ROS) are implicated in vascular homeostasis. This study investigated whether ${O_2}^{\cdot^-}$, the foundation molecule of all ROS, regulates vasomotor function. Hence, vascular reactivity was measured using rat thoracic aortas exposed to an ${O_2}^{\cdot^-}$ generator (pyrogallol) which dose-dependently regulated both $\alpha$-adrenergic agonist-mediated contractility to phenylephrine and endothelium-dependent relaxations to acetylcholine. Pyrogallol improved and attenuated responses to acetylcholine at its lower (10 nM - 1 ${\mu}M$) and higher (10 - 100 ${\mu}M$) concentrations, respectively while producing the inverse effects with phenylephrine. The endothelial inactivation by L-NAME abolished acetylcholine-induced vasodilatations but increased phenylephrine and KCl-induced vasoconstrictions regardless of the pyrogallol dose used. Relaxant responses to sodium nitroprusside, a nitric oxide donor, were not affected by pyrogallol. Other ROS i.e. peroxynitrite and $H_2O_2$ that may be produced during experiments did not alter vascular functions. These findings suggest that the nature of ${O_2}^{\cdot^-}$-evoked vascular function is determined by its local concentration and the presence of a functional endothelium.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.10-18
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• 1996

Experiments were carried out to find the possibility of an economic production of single cell protein(SCP) in mixed culture by Cellulomonas sp. KL-6 and a second organism. The second organism, strain LI-10, was isolated from the large intestines of a mouse. 1. When these strains were mixed, cell growth and carboxymethyl cellulase (CMCase) activity were increased to about 63% and 161%, respectively compared with that of single culture of strain KL-6. We found the mixed culture as a proper method of degradation of cellulose in our study. 2. Strain LI-10 was identified as E. coli. 3. This strain produced trace amounts of cellobiose, but glucose was not found in detectable amounts in the filter paper(FP) medium. 4. $CaCO_3$ injected in the medium at the ratio of 0.1% not only enhanced cell growth but also was effective as an acid neutralizing agent. 5. When this organism was cultured under the optimal medium (glucose 0.1%, $NH_4Cl$ 0.1%, yeast extract 2.0%, $KH_2PO_4$ 0.1%, KCl 0.05%, pH 7.2 and a temperature 30$\circ$C) for 5 days, a cell mass produced 1.18 g/l. The results showed the increase of cell mass up to 300% compared to 0.28 g/l produced in CMC medium.

• Journal of Powder Materials
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• v.9 no.5
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• pp.315-321
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• 2002

Pure tantalum powder has been produced by combining Na as a reducing agent, $K_2TaF_{7}$ as feed material, KCl and KF as a diluent in a stainless steel(SUS) bomb, using the method of metallothermic reduction. The present study investigated the effect of the amount of the diluent and reaction temperature on the characteristics of tantalum powder in the production process. The temperature applied in this study $850^{\circ}C$ and the amount of the additional reductant from +5% of the theoretical amount used for the reduction of the entire $K_2TaF_{7}$. The results showed that as the amount of the diluent increased, the reaction temperature became lower because the diluent prevented a temperature rise. Also, according to the mixture ratio of the feed materials and the diluent changed from 1 : 0.25 to 1 : 2, the particle size decreased from $5\mutextrm{m}$ to $1\mutextrm{m}$ and a particle size distribution which is below 325 mesh in fined powder increases from 71% to 83%. The average size of Tantalum powder, $2-4\mutextrm{m}$, was close to that of the commercial powders($2-5\mutextrm{m}$). Also under this condition, impurities contained in the powder were within the range allowed for the commercial Ta powders.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.329-332
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• 2001

The stability of red pigment isolated from RF101 was determined over a period of storage for the pH, light, temperature and various metal ions. The absorption maximum of red pigment was 510nm. Red pigment was stable from pH 5 to pH 9 and in dark conditions. It was also stable against temperature below $25^{\circ}C$ and in $K^+$, $Ca^{2+}$, $Mg^{2+}$, Antibacterial activity of RF101 showed growth-inhibitory activity against plant pathogens Agrobacterium spp.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.460-465
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• 2003

A bacterium, named as strain KL34, producing extracellular pectinase was isolated from soil. The mophological cheracteristics of the isolated bacterium were gram-negative, rod-shaped and endospore unformed. Production of pectinase of strain KL34 was induced only by polygalacturonic acid added to the culture media as a sole carbon source. Pectinase activity of KL34 reached a maximum value in the culture conditions of pH 8.5 at $25^{\circ}C$. Optimal medium for pectinase production was determined to the composition of 2% polygalacturonic acid, 0.25% yeast extract, 0.02% $K_2HPO_4$, 0.02% $CaCl_2$, and 0.05% KCl per liter. The pectinase activity in the culture supernatant reached the highest amount of 54 U/ml after 3 days cultivation in the optimal media.

• Journal of Marine Bioscience and Biotechnology
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• v.11 no.2
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• pp.89-93
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• 2019

In this study, the stability of the extracted natural pigments against light, temperature, pH, metal ions, and antimicrobial activity were evaluated in marine bacteria Zooshikella sp. 17TA. The pigment of the strain used in the study was red with maximum absorption at a wavelength of 541 nm. The stability of the pigment was evaluated by measuring the absorbance while preserving for 15 days and examining the retention rate. After 15 days of irradiation, the pigment of this bacterium showed 98% retention in the dark and 91% retention in the temperature range of -20℃ ~ 30℃. When the pH was in the range 4-7, the retention was about 80%, and the retention rate was higher than 85% for all kinds of metal ions except for CuCl₂, ZnCl₂, and KCl. The bacterial pigments showed high stability under the given irradiated pH, temperature, and metal ion conditions and had shown activity against gram-positive strains. These results suggest that this highly conserved microbial pigment can be applied to the food industry.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.963-968
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• 2010

This study has carried out to evaluate the performance of direct and indirect oxidation electrode for the purpose of decolorization of Rhodamine B (RhB) in water. Four kinds of electrodes were used for comparison: Pt and JP202 (indirect oxidation electrode), Pb and boron doping diamond (BDD, direct oxidation electrode). The effect of applied current (0.5 ~ 2.5 A), electrolyte type (NaCl, KCl, HCl, $Na_2SO_4$ and $H_2SO_4$) and electrolyte concentration (0.5 ~ 2.5 g/L), solution pH (3 ~ 11) and initial RhB concentration (25 ~ 125 mg/L) were evaluated. Experimental results showed that RhB removal efficiency were increased with increase of current, NaCl dosage and decrease of the pH. However, the effect of operating parameter on the RhB removal were different with the electrode type. JP202 electrode was the best electrode from the point of view of performance and energy consumption. The order of removed RhB concentration per energy lie in: JP202>Pt>Pb>BDD.

• Journal of Hydrogen and New Energy
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• v.27 no.4
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• pp.365-371
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• 2016

Cell performance of the Zn-Br redox flow battery (ZBRFB) using two different type's membrane (Nafion117 and SF-600) was evaluated at $20mA/cm^2$ of current density in 1M (mol/L) $ZnBr_2$ + 2M KCl + 0.3M EMPBr(1-ethyl-1-methyl pyrrolidinium bromide) electrolyte. The average energy efficiencies of ZBRFB were 74.9% and 74.7% for Nafion117 and SF-600, respectively. The electrolyte added the 1-ethyl-3-methylimidazolium dicyanamide (EMICA) as an additive was tested for the electrolyte in ZBRFB using SF-600 at $30mA/cm^2$ of current density. An average energy efficiency of the ZBRFB was 74.5% and 77.4% for the electrolyte non-added EMICA and added 1wt% of EMICA, respectively. ZBRFB using the electrolyte added EMICA was showed the higher performance than that using the electrolyte non-added EMICA.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.118-124
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• 2005

In this research, we examined the effect of NaCl on the growth, energy metabolism, and proton motive force of Halomonas salina, and the effect of compatible solutes on the bacterium growing in the high salinity environment. H. salina was isolated from seawater and identified by 16srDNA sequencing. The growth of H. salina was not enhanced by the addition of external compatible solutes (choline and betaine) in the high salinity environment. The resting cells of H. salina absorbed more glucose in the presence of 2.0 M NaCl than in its absence. H. salina did not grow in the medium with either KCl, RbCl, CsCl, $Na_2SO_4$, or $NaNO_3$, in place of NaCl. The optimal concentration of NaCl for the growth of H. salina ranged from 1.4 M to 2.5 M, and the growth yield was decreased in the presence of NaCl below 1.4M and above 2.5M. The activity of isocitrate dehydrogenase, pyruvate dehydrogenase, and malate dehydrogenase of H. salina was not inhibited by NaCl in in vitro test. The proton translocation of H. salina was detected in the presence of NaCl only. These results indicate that NaCl is absolutely required for the normal growth and energy metabolism of H. salina, but the bacterial growth is not enhanced by the compatible solutes added to the growth medium.

• Mycobiology
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• v.34 no.2
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• pp.73-78
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• 2006

Inter-specific hybridization between Pleurotus pulmonarius and P. florida was attempted through PEG-induced protoplast fusion to select a fusant. The protocol for protoplast release, regeneration and fusion in these two Pleurotus species was standardized using the variables controlling the process. The mixture of mycolytic enzymes, i.e. commercial cellulase, crude chitinase and pectinase, KCl (0.6 M) as osmotic stabilizer, pH 6 of the phosphate buffer and an incubation time of 3 hours resulted in the maximum release of protoplasts from 3-day-old mycelia of P. florida ($5.3{\sim}5.75{\times}10^{7}$ protoplasts/g) and P. pulmonarius ($5.6{\sim}6{\times}10^{7}$ protoplasts/g). The isolated protoplasts of P. florida regenerated mycelium with 3.3% regeneration efficiency while P. pulmonarius showed 4.1% efficiency of regeneration. Polyethyleneglycol (PEG)-induced fusion of protoplasts of these two species resulted in 0.28% fusion frequency. The fusant produced fruiting bodies on paddy straw but required a lower temperature of crop running ($24{\pm}2^{\circ}C$) than its parents which could fruit at $28{\pm}2^{\circ}C$. The stable fusant strain was selected by testing for the selected biochemical markers i.e. Carbendazim tolerance and utilization of the lignin degradation product, vanillin.