• Journal of Life Science
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• v.28 no.9
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• pp.1056-1061
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• 2018

This article reports an agar-degrading marine bacterium and characterizes its agarase. The agar-degrading marine bacterium, KC-1, was isolated from seawater on the shores of Sacheon, in Gyeongnam province, Korea, using Marine Broth 2216 agar medium. To identify the agar-degrading bacterium as Agarivorans sp. KC-1, phylogenetic analysis based on the 16S rRNA gene sequence was used. An extracellular agarase was prepared from a culture medium of Agarivorans sp. KC-1, and used for the characterization of enzyme. The relative activities at 20, 30, 40, 50, 60, and $70^{\circ}C$ were 65, 91, 96, 100, 77, and 35%, respectively. The relative activities at pH 5, 6, 7, and 8 were 93, 100, 87, and 82%, respectively. The extracellular agarase showed maximum activity (254 units/l) at pH 6.0 and $50^{\circ}C$ in 20 mM of Tris-HCl buffer. The agarase activity was maintained at 90% or more until 2 hr exposure at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$, but it was found that the activity decreased sharply from $60^{\circ}C$. A zymogram analysis showed that Agarivorans sp. KC-1 produced 3 agar-degrading enzymes that had molecular weights of 130, 80, and 69 kDa. A thin layer chromatography analysis suggested that Agarivorans sp. KC-1 produced extracellular ${\beta}$-agarases as it hydrolyzed agarose to produce neoagarooligosaccharides, including neoagarohexaose (21.6%), neoagarotetraose (32.2%), and neoagarobiose (46.2%). These results suggest that Agarivorans sp. KC-1 and its thermotolerant ${\beta}$-agarase would be useful for the production of neoagarooligosaccharides that inhibit bacterial growth and delay starch degradation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.381-387
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• 2015

This study was firstly conducted to investigate changes of vegetation and soil characteristics in reclaimed land applied with solidified sewage sludge for the cultivation of bioenergy crops. Each vegetation survey site was approximately $15m{\times}3m$ on the inside of each experimental plot that consisted of 50% (A-1), 30% (A-2), 15% (A-3), and 5% (A-4) mixture of solidified sewage sludge, and original reclaimed soil (ORS). After the application of solidified sewage sludge, we monitored the changes of vegetation and soil properties for three years. In first year, soil pH, electrical conductivity (EC) and exchangeable $Ca^{2+}$ content was 9.4~10.8, $9.10{\sim}14.41\;dS\;m^{-1}$, and $62.1{\sim}204.2\;cmol\;kg^{-1}$, respectively, while three years later, it decreased to 8.1~8.4, $1.65{\sim}5.98\;dS\;m^{-1}$, and $21.9{\sim}43.1\;cmol\;kg^{-1}$, respectively. These results indicated that several of soil chemical elements which have nagative impacts on the plant growth in the plots of mixtures of solidified sewage sludge, steadily declined as the years go by. The vegetations in each survey site were recorded as 6 families and 12 species in 2014, while the vegetations were not occurred at all survey sites in 2012, and only halophytes as Phragmites australis and Suaeda asparagoides were observed in 2013. Diversity of vegetation, which was calculated by shannon index (H'), increased as the season progressed at each experimental plot applied with solidified sewage sludge. In original reclaimed soil, however, there was showed the high community similarity of vegetation due to the fact that P. australis and S. asparagoides were only occurred for survey periods.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.89-99
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• 2004

Stretch-activated channels (SACs) responds to membrane stress with changes in open probability (Po). They play essential roles in regulation of cell volume and differentiation, vascular tone, and in hormonal secretion. SACs highly present in Xenopus oocytes and Ascidian oocytes are suggested to be involved in the regulation of pH and fluid transport to balance the osmotic pressure, but remain unclear in mammanlian oocytes. This study was investigated to find the presence of SACs in hamster oocytes and to examine their electrophysiological properties. To infer a role of SAC in relation to the development of early stage, we followed up to the stage of two-cell zygote with patch clamp techniques. Single channels were elicited by negative pressure (lower than ­15 cm$H_2O$). Interestingly, SACs were dependent on permeable cations such as $Na^+$ or $K^+$. As permeable cation removed from both sides across the membrane, SAC activity completely disappeared. When permeable cations present only in intracellular compartment, outward currents appeared at positive potentials. In contrast to this, inward currents occurred only at the negative voltage when permeable cation absent in cell interior. These result suggests that SAC carry cations through the nonselective cation channel (NSC channel). Taken together, we found that stretch activated channels present in hamster oocyte and the channel may carry cations through NSC channels. This stretch activated-NSC channels may play physiological role(s) in oocyte growth, maturation, fertilization and embryogenesis in fertilized oocytes to two-cell zygotes of hamster.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.173-183
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• 2004

This study was carried out to examine the effects of epidermal growth factor (EGF) and the number of cumulus-oocyte complexes (COCs) on in vitro maturation (IVM) of porcine immature oocytes, and on subsequent in vitro fertilization (IVF) and development (IVD). COCs were collected from antral follicles of porcine ovaries collected from abattoir, and were maturated in modified NCSU-23 (mNCSU-23) with 10% pFF, 0.6 mM cysteine, 50 ${\mu}mM{\beta}-mercaptoethanol$, 1 mM dbcAMP, 10 IU/mL PMSG and 10 IU/mL hCG, which was supplemented with or without 10 ng/mL EGF and into which 50 or 15 COCs per droplet was put. Oocytes matured in vitro, were fertilized in vitro in modified Tris-buffered medium (mTBM) with the final motile sperm concentration of 1${\times}$105 sperm/mL, and subsequently putative embryos were developed in vitro in NCSU- 23. The results are as follows. 1.In the result of IVM, 10 ng/mL EGF supplement duplicated the percentage of C4 group of COCs(41% vs 81%). But the rate of germinal vesicle breakdown (GVBD) and of nuclear maturation were not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, and there was not a significant interaction between the two factors, either. 2. In the result of IVF, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, or was not a significant interaction between the two factors, in the rate of sperm penetration, in the percentage of oocytes with male pronucleus (MPN), and in the rate of polyspermy. 3. In the result of IVD, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet in the percentage of cleaved oocytes. There was not significantly different between the number of COCs per culture droplet, but between control and EGF supplemented (p<0.01) in the percentage of blastocysts, the number of inner cell mass (ICM), trophectoderm (TC) and total cells. There was no significant interaction between the two factors anywhere. These results suggested that 10 ng/mL EGF supplement into mNCSU-23 for IVM was effective in the production of more as well as better blastocysts during IVD through increasing the number of cells in those.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.434-440
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• 2013

This study was conducted to screen the characteristics and alginate-degrading activity of marine bacterium isolated from brown seaweed (Sargassum thunbergii). The results of 16S ribosomal RNA sequence analysis the strain the genus Vibrio and the strain was subsequently named Vibrio sp. PKA 1003. The optimum culture conditions for the growth of Vibrio sp. PKA 1003 were at pH 7, 3% NaCl, $25^{\circ}C$, and 6% alginic acid, with a 48-hour incubation time. A crude enzyme preparation from Vibrio sp. PKA 1003, showed its highest levels of alginate-degradation activity when cultured at pH 9, $30^{\circ}C$, and 6% alginic acid, with a 63-hour incubation time. Thin layer chromatography analyses confirmed that the crude enzyme released monomers or oligomers from sodium alginate, and results from trypsin treatment showed that the alginate degrading activity depends on this enzyme produced by Vibrio sp. PKA 1003. These results suggest that Vibrio sp. PKA 1003 and its alginate-degrading crude enzyme is useful for the production of alginate oligosaccharides.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.742-750
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• 2006

This study was carried out to investigate the efficacy of two kinds of electrolyzed water with added 0.5% (v/v) citron juice, SAEW-CJ[Strong Acidic Electrolyzed Water with added Citron Juice, pH 2.57, ORP (oxidation-reduction potential) 1,122 mV, HClO 23.05ppm] and LAEW-CJ (Low Alkaline Electrolyzed Water with added Citron Juice, pH 4.67, ORP 997mV, HClO 42.55mV) as storing liquid for peeled taro. During storage at $5^{\circ}C$ until 30 days, SAEW-CJ and LAEW-CJ inhibited the growth of microorganisms more effectively than 0.2% (w/v) APS (aluminium potassium sulfate) and 0.85% (w/v) NaCl did. Total phenolic contents, PRO (polyphenol oxidase) activity, color differences value (${\Delta}E$) and vitamin C contents of peeled taro stored in SAEW-CJ and LAEW-CJ were lower than those stored in 0.2% APS and 0.85% NaCl. The hardness decrement of peeled taro stored in LAEW-CJ was lower than that of the others. In addition, the contents of moisture, crude protein, crude ash, total sugars, and reducing sugars were gradually decreased during storage. However, no difference by peeling methods or immersion liquid was found.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.18-24
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• 1985

A pot experiment was conducted to study the influence of potassium and cesium carrier on the uptake of radionuclide $Cs^{137}$ which is an element released usually from nuclear facilities, by paddy rice upon prolonged cropping of contaminated soils. The results are summarized as follows: 1) Visual toxic symptoms on the growth of rice plant due to treatment of radioactive cesium were not observed up to $20 {\mu}Ci/10Kg$ soil in a pot. 2) The yield and potassium content in rice plant were increased with potassium application, while the reverse was true for the calcium and magnesium. The addition of potassium to the soil markedly reduced $Cs^{137}$ uptake by rice plant but the addition of Cs carrier increased $Cs^{137}$ uptake. 3) Potassium and $Cs^{137}$ showed uniform distribution in all parts of plant and the contents of these two elements were high in the stems and leaves, and low in the heads. The ratio of $Cs^{137}$ to K was, however, not uniform in all parts of a plant. It was shown that this ratio was higher in the seed part, that is, chaff and hulled grain than in the leaves and stems. 4) $Cs^{137}$ absorption rate in rice plant was remarkably reduced with increase of potassium application and it was ranged from $0.02{\sim}0.47%$ in potassium non-treated plot to 0.01∼0.04% in plot treated with a concentration of 16Kg/10a. 5) The amount of $Cs^{137}$ and potassium uptake of rice plant depended on soil type. Uptake of $Cs^{137}$ by rice plant was higher in the soil with low pH and potassium content. The $Cs^{137}$ uptake by rice plant decreased as the potassium content and pH of soil was increased, but $Cs^{137}$ uptake increased when CEC and clay content in soil was high.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.79-86
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• 2017

Microbes in forest are very important due to not only to enhance soil fertility but also maintain a healthy ecosystem by supplying the energy available to living organisms by producing various kinds of enzymes related to degradation of lignocellulosic biomass. In order to isolate a lignocellulosic biomass degrading bacterial strain from the Jurassic park located in Gyeongnam National University of Science and Technology, We used the Luria-Bertani-Carboxymethyl cellulose (CMC) agar trypan blue method containing 0.4 % carboxymethyl cellulose and 0.01 % trypan blue. As a result, we isolated a bacterial strain showing both activity on the CMC and xylan. To identify the isolated strain, 16S rRNA sequencing and API kit analysis were used. The isolated strain turned out to belong to Bacillus species and then named Bacillus sp. GJY. In the CMC zymogram analysis, it showed that one active band of about 28kDa in size is present. Xylan zymogram analysis also showed to have one active band of about 25kDa in size. The optimal growth temperature of Bacillus sp. GJY was $37^{\circ}C$. The maximal activities of CMCase and xylanase were 12 hour after incubation. The optimal pH and temperature for CMCase were 5.0 and $40^{\circ}C$, respectively, whereas the optimal pH and temperature for xylanase was 4.0 and $40^{\circ}C$. Both activities for CMCase and xylanase showed to be thermally stable at 40and $50^{\circ}C$, while both activities rapidly decreased at over $60^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.152-157
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• 2016

BACKGROUND: Since bottom ash (BA) contains considerable amounts of CaO and MgO, it could be a useful amendment to increase soil pH and to immobilize cadmium (Cd). This study was conducted to evaluate effect of BA application in reducing Cd phytoavailability.METHODS AND RESULTS: Bottom ash was applied at the rate of 0, 20, 40, and 80 Mg/ha to Cd contaminated soil, and then lettuce was cultivated under field condition. soil pH and net negative charge increased slightly with increasing BA application; however, there was no statistical difference among the rates. Water soluble, exchangeable+acidic, reducible, and oxidizable fraction of Cd decreased with increasing bottom ash application rate, whereas residual fraction of Cd increased with increasing bottom ash application rate. Lettuce yield increased with rate of bottom ash up to 40 kg/ha. Visual evidences of cadmium toxicity and growth inhibition were not found during lettuce cultivation.CONCLUSION: Bottom ash was effective to reduce phytoextractability of Cd and to increase lettuce yield. Conclusively, BA could be a good soil amendment to reduce Cd phytoavailability in contaminated arable soil.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.128-134
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• 2012

Foot and mouth disease (FMD) is one of the most notorious and contagious viral diseases afflicting cloven-hoofed animals. In this study, the physicochemical properties of leachate from a FMD landfill site at 773-1, Waryong, Andong, Korea and the ground water from 777, Waryong, Andong, Korea, were analyzed for 1 year from December $10^{th}$ 2010 to November $17^{th}$ 2011. The leachate was collected from the FMD landfill site during March, May, July, September and November, 2011 and changes in pH, brix, water content, insoluble solids, crude proteins, crude lipids, total and reducing sugars and ash content were determined. Considering the annual profiles of temperature and rainfall at the FMD landfill site, the dramatic changes in the physicochemical properties of the leachate from March to July, and especially from May to July, such as increases in pH, and a rapid reduction of brix and organic matter, may be closely linked to the growth of microorganisms in the leachate. The sharp decreases in the concentration of biominerals, such as Mg, Ca, and Fe from 1073, 4311 and 56.2 ppm in March to 151, 78, and 0.1 ppm in November, further suggest that decreases in organic matter in the leachate result from degradation by microorganisms originating from the intestines of the livestock. Analysis of the profiles of the organic materials in the leachate revealed that the properties of the leachate were similar to those of excremental matter-derived water. These results could be applied to a number of fields for the analysis of organic matter behavior, the development of the degradation process, and risk analysis in the environment for hygiene and food industries, of leachate from FMD landfill sites.