• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.403-412
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• 2021

This study aimed to identify plant growth-promoting activity, phytopathogenic fungi growth inhibitory activity, mineral solubilization ability, and extracellular enzyme activity of the genus Bacillus in soil and the rhizosphere. With regards to antifungal activity against phytopathogenic fungi, DDP257 showed antifungal activity against all 10 pathogenic fungi tested. ANG20 showed the highest ability to produce indole-3-acetic acid, a plant growth-promoting factor (70.97 ㎍/ml). In addition, 10 species were identified to have 1-aminocyclopropane-1-carboxylate deaminase production ability, and most isolates showed nitrogen fixation and siderophore production abilities. Thereafter, the isolated strains' ability to solubilize minerals such as phosphate, calcite, and zinc was identified. With extracellular enzyme activity, the activity appeared in most enzymes. In particular, all the strains showed similar abilities for alkaline phosphatase, esterase (C4), acid phosphatase, and naphtol-AS-BI-phosphohydrolase production. This result was observed because the genus Bacillus secreted various organic substances, antibiotics, and extracellular enzymes. Therefore, through the results of this study, we suggest the possibility of using strains contributing to the improvement of the soil environment as microbial agents.

• Journal of Ginseng Research
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• v.16 no.3
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• pp.198-209
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• 1992

The decreased activities of liver enzymes relating to carbohydrate metabolism such as glucose- 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and acetyl CoA carboxylase of streptozotocin injected rats were significantly modified by the intraperitoneal injection of ginseng saponin mixture and/or purified ginsenosides. However, several enzymes such as pyruvate kinase, malic enzyme and glycogen phosphorylase were not modified appreciably by the saponin administration, suggesting that the effect of ginseng saponin might be depend upon individual enzymes. Examination of liver enzymes by liver professing technique using perfusion buffer containing saponin (10-3%) showed that the ginseng saponin might stimulate insulin biosynthesis as well as the related enzyme activities.

• Archives of Pharmacal Research
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• v.16 no.2
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• pp.155-157
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• 1993

DNA transfection conditions were investigated by calcium phosphate-DNA co-precipitation in SK-N-BE(2)C human neuroblastoma cells. The DNA plasmid of TH2400CAT was used in which rat tyrosine hydroxylase gene was inserted into chloramphenicol acetyltransferase reporter gent. The transfection efficiency was 25-30% and the method was simple and reproducible. So, the method will be a good tool for transient transfection analysis.

• KSBB Journal
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• v.25 no.6
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• pp.559-564
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• 2010

A new hydrogen-oxidizing bacterium, Aeromonas sp. strain JS-1, that can fix $CO_2$ via the reductive pentose phosphate cycle (Calvin-Benson cycle) under chemoautotrophic conditions but not photoautotrophic conditions was isolated from fresh water. Strain JS-1 showed considerable $CO_2$ fixation ability during continuous cultivation even at high $CO_2$ concentration. Strain JS-1 used $H_2$ and $CO_2$ fixation as energy and carbon sources, respectively. Carbon dioxide fixation is carried out through the Calvin-Benson cycle, in which ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) is the key enzyme. Hydrogen-oxidizing chemoautotrophic Aeromonas sp. strain JS-1 exhibited remarkedly strong RubisCO [EC 4.1.1.39] activity. RubisCO was purified as an $L_8S_8$-type hexadecamer with molecular mass of 560 kDa by gel filtration. The enzyme consisted of two different subunits eight large (56 kDa) and eight small (15 kDa), as demonstrated by SDS-PAGE. The specific activity of the purified enzyme was about 3.31 unit/mg and stable up to $45^{\circ}C$. The $K_m$ values for RuBP, $CO_2$, and $Mg^{2+}$ were estimated to be 0.25 mM, 5.2 mM and 0.91 mM, respectively.

• Ocean and Polar Research
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• v.30 no.3
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• pp.325-334
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• 2008

A biogeochemical model was used to estimate air-sea $CO_2$ exchange over the East China Sea. Since fresh water discharge from the Changjiang River and relevant chemistry were not considered in the employed model, we were not able to produce accurate results around the Changjiang River mouth. This factor aside, the model showed that the East China Sea, away from the Changjiang River mouth, takes approximately $1.5{\sim}2\;mole\;m^{-2}yr^{-1}$ of $CO_2$ from the atmosphere. The model also showed that biological factors modify the air-sea $CO_2$ flux by only a few percent when we assumed that biological activity increased two-fold. Therefore, we can argue that the biological effect is not strong enough over this area within the framework of the current phosphate-based biological model. Compared to the preindustrial era, in 1995 the East China Sea absorbed $0.4{\sim}0.8\;mole\;m^{-2}yr^{-1}$ more $CO_2$. If warming of the sea surface is considered, in addition to the increase in atmospheric $CO_2$ concentration, by 2045 the East China Sea would absorb $0.2{\sim}0.4\;mole\;m^{-2}yr^{-1}$ less $CO_2$ compared to the non-warming case.

• Applied Biological Chemistry
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• v.7
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• pp.45-52
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• 1966

This study was carried out to determine how the water soluble, the available $P_2O_5$ and urea-N would change in the course of time, when the mixtures of calcium superphosphate and urea with lime for fertilizer which occurred in Korea and largely contained calcium carbonate were made. Three kinds of materials, i. e., calcium superphosphate, urea and lime for fertilizer were used in this study. Three kinds of mixed fertilizer, i. e., A, B and C were made up by mixing these materials to satisfy the following formula. $$1)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_2H_2(PO_4)+H_2CO_3+NH_3$$ $$2)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+NH_3$$ $$3)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+CaCO_3+NH_3$$ A,B and C were placed in desiccators respectively a six month period. During the time of storage, the water soluble, the available phosphoric acid and urea-N were measured once a month, seven times with the control measurement. The results may be summarized as follows. 1. None of A, B and C showed any change in the urea-N with the lapse of time. This fact indicated that the combination of calcium superphosphate and urea with lime for fertilizer was not unfavourable. 2. A, B and C decreased in the amount of water soluble $P_2O_5$ with the passage of time. This fact indicated that the mixing of calcium superphosphate and urea with lime for fertilizer was unfeasible. 3. The available $P_2O_5$ in any of A,B and C did not undergo a change as time went by. This fact suggested that the combination of calcium superphate and urea with lime for fertilizer was favourable.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.715-723
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• 2018

The present study was done to investigate the effect of co-culturing muscle satellite cells (MSCs) and intramuscular preadipocytes (IPs) on the differentiation of adipocytes and muscle cells isolated from Korean native cattle. MSCs and IPs were single-cultured in 10% fetal bovine serum/Dulbecco's modified Eagles medium (FBS/DMEM) for 48 h followed by culturing in 5% FBS/DMEM as the growth media. Then, the growth media was replaced by differentiation media composed of 2% FBS/DMEM without any additives for the single- or co-culture of muscle cells and intramuscular adipocytes to induce the differentiation of both cell types. Cell differentiation was measured by morphological investigation and cytosolic enzyme analysis of glycerol-3-phosphate dehydrogenase (GPDH) for the adipocytes and creatine kinase (CK) for the muscle cells. In the morphological test, the presence of muscle cells did not stimulate adipocyte differentiation showing more differentiation of the adipocytes in the single-culture compared to the co-culture condition. However, the differentiation of muscle cells was promoted by adipocytes in the co-culture. The results of the enzymatic analysis were highly associated with the morphological results with a statistically higher GPDH activity (p < 0.05) appearing in the single-culture than in the co-culture, whereas the opposite was true for the CK activity of the muscle cells (p < 0.05). By manipulating in vivo the milieu using a co-culture, we could detect the difference in the rate of cell differentiation and suggest that a co-culture system is a more reliable and precise technique compared to a single-culture. Further studies on various co-culture trials including supplementation of differentiating substances, gene expression analysis, etc. should be done to obtain practical and fundamental data.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.425-431
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• 1996

The enzymatic characteristics of Alcaligenes latus were investigated by measuring the variations of various enzyme activities related to biosynthesis and degradation of poly-${\beta}$-hydroxybutyrate (PHB) during cultivation. All PHB biosynthetic enzymes, ${\beta}$-ketothiolase, acetoacetyl-CoA reductase, and PHB synthase, were activated gradually at the PHB accumulation stage, and the PHB synthase showed the highest value among three enzymes. This indicates that the rate of PHB biosynthesis is mainly controlled by either ${\beta}$-ketothiolase or acetoacetyl-CoA reductase rather than PHB synthase. The enzymatic activities related to the degradation of PHB were also measured, and the degradation of PHB was controlled by the activity of PHB depolymerase. The effect of supplements of metabolic regulators, citrate and tyrosine, was also investigated, and the activity of glucose-6-phosphate dehydrogenase was increased by metabolic regulators, especially by tyrosine. The activities of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase were also activated by citrate and tyrosine, while the activity of PHB depolymerase was depressed. The increased rate and yield of PHB biosynthesis by metabolic regulators may be due to the increment of acetyl-CoA concentration either by the repression of the TCA cycle by citrate through product inhibition or by the activation of sucrose metabolism by the supplemented tyrosine.

• Polymer(Korea)
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• v.30 no.4
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• pp.286-292
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• 2006

Super water-absorbent resins were prepared by inverse suspension copolymerization of sodium acrylate, acrylamide and 2-hydroxyethyl acrylate using N, N'-methylene-bis-acrylamide as cross-linker. For the suspension copolymerization, monohexadecyl phosphate was employed as the dispersing agent, cyclohexane as the dispersing medium and potassium persulfate as the initiator. The dependence of water-absorption capacity on the amount of crosslinking agent, oil/water ratio, degree of neutralization and the composition of the copolymer were systematically investigated. Furthermore, the swelling kinetics of the super water-absorbent copolymer was carried out. The absorption of the resins is more than 1800 g/g for deionized water and 100 g/g for 0.9% NaCl solution, respectively. The copolymers showed an increased salt resistance and enhanced water retention of soil.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.23-27
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• 1997

To investigate the effect of L-arginine as stabilizing agent for omeprazole, the degradation rate constant of omeprazole in aqueous solution was determined at 30, 40 and $50^{\circ}C$ with various ratios of L-arginine to omeprazole. The pH of omeprazole solutions was also determined. As the amount of L-arginine increased, the pH of omeprazole solution also increased, and the solution appeared to be more stable. The omeprazole in aqueous solution could be stabilized by more than 15:1 molar ratio of L-arginine to omeprazole. The stability of omeprazole in commercial products using L-arginine or sodium phosphate dibasic as stabilizing agent was investigated. Among the commercial products, the omeprazole product prepared with L-arginine (molar ratio of L-arginine to omeprazole, 20:1) was most stable.