• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.458-468
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• 2007

To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.529-542
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• 2020

The cesium (Cs) sorption characteristics of a bead-type polysulfone carrier contained HNO₃-treated bamboo charcoal (3 - 5 mm in diameter) in water system were investigated and its Cs removal efficiency as an adsorbent from water was also identified by various laboratory experiments. From the results of batch sorption experiments, the bead-type polysulfone carrier with only 5% HNO₃-treated bamboo charcoal (P-5NBC) represented the high Cs removal efficiency of 57.8% for 1 hour sorption time. The Cs removal efficiency of P-5NBC in water after 24 hours reaction maintained > 69% at a wide range of pH and temperature conditions, attesting to its applicability under various water systems. Batch sorption experiments were repeated for P-5NBC coated with two cultivated microorganisms (Pseudomonas fluorescens and Bacillus drentensis), which were typical indigenous species inhabited in soil and groundwater. The Cs removal efficiency for two microorganisms coated polysulfone carrier (BP-5NBC) additionally increased by 19% and 18%, respectively, compared to that of only P-5NBC without microorganisms coated. The average Cs desorption rate of P-5NBC for 24 h was lower than 16%, showing the Cs was stably attached on HNO₃-treated bamboo charcoal in so much as its long-term use. The maximum Cs sorption capacity (q_m) of P-5NBC calculated from the Langmuir isotherm model study was 60.9 mg/g, which was much higher than those of other adsorbents from previous studies for 1 h sorption time. The results of continuous column experiments showed that the P-5NBC coated with microorganisms packed in the column maintained > 80% of the Cs removal efficiency during 100 pore volumes flushing. It suggested that only 14.7 g of P-5NBC (only 0.75 g of HNO₃ treated bamboo charcoal included) can successfully clean-up 7.2 L of Cs contaminated water (the initial Cs concentration: 1 mg/L; the effluent concentration: < 0.2 mg/L). The present results suggested that the Cs contaminated water can be successfully cleaned up by using a small amount of the polysulfone carrier with HNO₃-treated bamboo charcoal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.1
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• pp.20-24
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• 2003

Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.

• Journal of the Mineralogical Society of Korea
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• v.7 no.2
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• pp.91-96
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• 1994

중.저준위 방사성 폐기물의 대표적인 핵종인 137Cs, 90Sr에 대한 캐올리나이트의 흡착특성을 수용액의 이온강도와 pH의 영양하에서 알아보았다. 흡착실험은 회분식으로 하였고, 사용한 수용액은 NaCl, CaCl2, MgSO4, KCL 각각을 10-1, 10-2, 10-3, 10-4 mole/$\ell$로 하였다. 수용액광물 평형상태의 pH를 4.5, 7.0, 10.5로 조절하였다. 실험결과 캐올리나이트의 Cs, Sr 흡착은 이온강도와 pH에 상당한 영향을 받으며, Sr 흡차에 양이온들의 경쟁은 Ca2+ Mg2+>K+>Na+ 순을 보이고, Cs의 경우에는 K+>Ca2+ Mg2+>Na+의 순을 보인다. 이는 수용액상에서 이온들의 수호에너지와 관련되며, 광물입자와 이온들의 물구조변환특성에 의해 설명된다. Cs과 Sr 사이에 흡착우선성은 산성 내지 약알카리에서는 Cs이 Sr보다 흡착이 잘 되나, 강알칼리성 환경에서는 Sr이 Cs보다 흡착이 잘 되는 pH 의존성을 보였다. 수용액의 pH가 증가함에 따라 핵종의 흡착량이 증가하는데, 이는 캐올리나이트의 흡착자리인 실라놀과 알루미놀에 의한 제타전위가 pH에 의존함과 잘 일치한다.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.451-456
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• 1998

By grafting acrylic acid, fumalic acid and maleic acid onto chitosan, graft copolymers, CsAa, CsFa and CsMa, respectively were prepared for potential uses as flocculants in waste water treatment. When 40 ppm of each grafted chitosan sample was added into the waste water, CsMa showed the best removal rate of COD and suspended solids(SS), followed by CsFa and CsAa and chitosan. The transmittance and removal rate of COD and SS were the highest at pH 5. All grafted chitosan exhibited better performance than chitosan itself, resulting from the amphiphilic property of grafted chitosan copolymer with carboxy groups.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.205-214
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• 2005

The purpose of this study was to investigate the effect of ground corn as an additive to ginseng residue silages. The silages were made with corn (CS), red ginseng (GS), red ginseng residue +0.5% ground corn (GS0.5), w/w bases, red ginseng residue+1.0% ground corn (GS1.0) and red ginseng residue+silage inoculant, lactic acid bacteria (GSL). The raw materials were cut only for corn forage in 2cm length. The ginseng residue without cutting were mixed without or with additives, ground corn and inoculant, and ensiled each into two 2,000ml glass bottles. The bottles with silages were stored at a dark place at room temperature and formented for 60 days. The crude protein contents were higher for all red ginseng silages as 17.7, 18.8, 18.3 and 17.8% for GS, GS0.5, GS1.0 and GSL than that of corn silage as 8.8% (p<0.05). The calcium content were higher in GS, GS0.5, GS1.0 and GSL as 0.99, 1.13, 0.99 and 1.03% than that in CS as 0.31% (p<0.05). The pH of silages fermented for 60 days was similar each other; CS, GS, GS0.5, GS1.0 and GSL as 3.8, 3.7, 3.3, 3.5 and 3.7, respectively. However the pH of GS0.5 was the lower than that of corn silage. The total concentration of volatile fatty acids were higher for CS as 87.3 mM/dl than those of GS, GS0.5, GS1.0 and GSL as 44.7, 37.8, 46.3 and 47.2 nM/dl. However, the percentage of lactic acid concentration of ginseng silages such as GS, GS0.5, GS1.0 and GSL, 60.2, 77.2, 83.4 and 77.3% was higher than that in CS, 53.7% (p<0.05). The in vivo dry matter digestibilities for 72hr fermentation was higher in ginseng silages (GS, GS0.5, GS1.0 and GSL as 76.5, 75.8, 72.9 and 77.3%, respetively) than that in for CS as 52.1% (p<0.05). It can be concluded that silage added with ground corn (GS0.5 and GS1.0) and lactic acid inoculant were high in its quality, and the GS0.5 can be suggested as a practical method for red ginseng residues silage making.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.213-218
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• 1998

A bacterium with potent activity of pigment production and protease was isolated and identified as being Bacillus sp. CS-17. Cell growth, protease activity and pigment production of the strain reached to its maximum point after 24 hrs, 48 hrs, 72 hrs, respectively. The best pigment producing ability of Bacillus sp. CS-17 was shown on basal medium for pigment production added 1.0% soybean. The high effcient conditions for pigment production was obtained at culture of pH 8.5, $37^{\circ}C$ and 72 hours. Among the tested 5 gram positive strains and 6 gram negative strains, weak antibacterial activity of pigment concentrated extracts was appeared against growth of B. subtilis, P. aeruginosa, S. typhimurium, E. aerogenes, B. cereus, A. hydrophila.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.251-257
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• 2006

This study was performed to investigate the growth rate, hematological and serological changes of the rats when they were fed with the high(at diets supplemented with or without chitosan for five weeks. Twenty-four Sprague-Dawley male rats($235.7{\pm}10.7g$ of body weight) were randomly divided into three groups control group(C) and two treatment groups. Rats in the control group were fed with the high-fat diet containing 10% lard, 1% cholesterol and 0.5% sodium cholate(w/w) which was modified from the formula of the American Institute of Nutrition-76(AIN-76) diet. Rats in treatment groups were red with above diet supplemented with 2.5% of chitosan(CS-2.5) or 5.0% chitosan(CS-5) on the weight to weight basis, respectively. The supplementation of chitosan did not induce any significant difference on the final body weight, gain of body weight and amount of feed intake of rats in between control and treatment groups but the feed efficiency of rats in CS-5 was lower than that of rats in C(p<0.05). The hemoglobin concentrations and hematocrit values showed no significant differences among groups. In addition the values of glucose concentration, total protein, albumin, globulin and albumin/globulin(A/G) ratio showed no significant differences among groups. The values of total cholesterol and low density lipoprotein-cholesterol(LDL-C) in sera of rats in CS-5 were lower than those in both C and CS-2.5(p<0.01). The values of high density lipoprotein-cholesterol (HDL-C) in sera of rats in CS-5 were higher than in both in C and CS-2.5(p<0.05). The values of atherogenic index(AI) of rats in CS-5 were the lowest among groups(p<0.01). AI of CS-2.5 were lower than that or C(p<0.05). The values of triglyceride in sera of rats showed no significant differences among groups. The values of AST in sera of rats in CS-2.5 were lower than those in both C and CS-5(p<0.05). However ALT values showed no significant differences among groups. Therefore the supplementation of chitosan to high fat diet reduced effectively the serum lipid levels such as total cholesterol, LDL-C and triglycerides which were regarded as to cause the cardiovascular diseases moreover it elevated effectively HDL-C value which was regarded protect cardiovascular diseases.

• Journal of Ginseng Research
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• v.27 no.4
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• pp.171-177
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• 2003

Previously we have reported that administration of Korean red ginseng water extract (KRG-WE) plays both preventive and therapeutic roles in testicular toxicity of guinea pigs exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Further study was carried out to verify the beneficial role of Korean red ginseng in TCDD-induced testicular toxicity with different animal species by different route of administration. Korean red ginseng crude saponin (KRG-CS) was prepared by Diaion HP-20 adsorption chromatography. One hundred twenty rats (Sprauge Dawley, 200${\pm}$10 g) were divided into 6 groups. The normal control group (NC) received vehicle (i.p.) and saline (p.o.). Predetermined dosage of TCDD (40 $\mu\textrm{g}$/kg b.w., i.p.) was administered to single TCDD-treated (TT) and test (CS) groups. KRG-CS was admin-istered (p.o.) at daily doses of 5 (CS5), 10 (CS10),20 (CS2O) and/or 40 mg/kg b.w. (CS40) for 5 weeks, starting 1 week before the TCDD-exposure. Body weight gain, organ weights, and sperm quality were investigated. Decrease in body weight gain induced by TCDD was greatly attenuated by KRG-CS in a dose-dependent manner. Testicular weight, sperm head counts and ratio of sperm with progressive movement in TT group decreased significantly but those parameters were improved by the treatment of KRG-CS in a dose-dependent manner. This result led us to conclude that crude saponin might be the active ingredient of Korean red ginseng that attenuates the testicular toxicity induced by TCDD.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.157-161
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• 2003

Proline is known as an osmoprotectant accumulating in response to salt and dehydration stresses. An increased level of proline is achieved by either an induced synthesis or a reduced degradation of proline. In an attempt to increase salt tolerance in carrot, a P5CS gene from mothbean was introduced via an Agrobacterium-mediated transformation. The resulting carrot cells and the regenerated plants containing the transgene showed increased levels of proline compared to nontransgenics. The transgenic cell line, Pj2 showed about 6 times increased degree of tolerance determined by relative growth after a treatment in 250 mM NaCl. In facts, due to the retarded growth shown in non-saline condition, Pj2 cells grow only about 1.2 times better than nontransgenic control under salt stress condition. Taken together, it appears that a P5CS is a key enzyme in proline biosynthesis and the increased accumulation of proline by overexpression of the enzyme is enough to enhance tolerance to salt stress in carrot.