• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.606-612
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• 2018

The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-${\beta}$-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was $80^{\circ}C$ and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at $60^{\circ}C$. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of $Ca^{2+}$ and $Zn^{2+}$ ions. The kinetic properties, $K_m$ and $V_{max}$, were calculated as 81.44 mM and $2.237{\mu}mol/min/mg$, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.

• Korean Journal of Plant Taxonomy
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• v.37 no.4
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• pp.545-563
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• 2007

The investigated vascular plants of Dok-do island were confirmed that consisted of 46 species, 1 subspecies, 1 varieties in total of 48 taxa growing spontaneously. 1 taxa of Pteridophyta, 36 taxa of Dicotyledon and 11 taxa of Monocotyledon identified. In 48 identified taxa in this study, total 13 taxa included Orobanche coerulescens Stephan, Fallopia sachalinensis (F. Schmidt) Rouse Decr., Lonicera insularis Nakai identified according to the Korean plant taxa for environmental assessment. Planting species were about 10 taxa included Pinus thunbergii Parl., Hibiscus syriacus L. and etc. Four species confirmed in this study such as between Chenopodium virgatum Thunb. and Chenopodium album L., Echinochloa crusgalli (L.) P.Beauv. and Echinochloa crusgalli var. oryzicola (Vasinger) Ohwi. were doubt on identification in taxonomic entity due to morphological characteristics. The dispersion type of Do-kdo plants were anemochore 31 taxa, zoodchore 8 taxa, hydrochore 2 taxa and the others by artificial means.

• Food Science and Preservation
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• v.18 no.2
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• pp.149-155
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• 2011

Cheonggukjang tablet was prepared by addition of medicinal herb extracts (from Lentinus edodes, Codonopsis lanceolata, or Houttuynia cordata Thunb.) to improve its quality and functional properties. Lightness and yellowness (measured using Hunter's color values) were generally increased with increasing amount of medicinal herb extracts, whereas pH decreased. In proximate composition, the levels of crude protein, lipid and fiber levels of Cheonggukjang tablet decreased with increasing amount of added medicinal herb extracts, whereas moisture and crude ash were increased. The major amino acid of Cheonggukjang tablet were glutamic acid, aspartic acid, leucine and the principal fatty acids of Cheonggukjang tablet were linolenic acid, linoleic acid and palmitic acid, respectively. Hardness levels of Cheonggukjang tablet decreased with increasing amounts of added medicinal herb extracts. The Cheonggukjang tablet added with medicinal herb extracts increased both crude saponin and quercetin contents. Sensory score of Cheonggukjang tablet containing 20% (w/v) medicinal herb extracts were optimal in terms of both quality characteristics and sensory evaluation.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.780-786
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• 1993

About 7.7% of the total anaerobic bacteria in pig feces grew with clear zone around the colonies on the agar medium containing inulin as a sole carbon source. Among these bacteria, a strain with the strongest inulin-utilizing activity was isolated and identified as Bacteroides sp. based on its morphological and taxonomical characteristics. The isolate grew well with inulin, fructooligosaccharides or glucose as a sole carbon source, while its growth dropped to 50% of that obtained with glucose when soluble starch or sucrose are used. Since the inulase activity was found only when fructooligosaccharides or inulin was added to the growth medium, but not when glucose, sucrose or soluble starch was applied, the inulase production was considered to be induced by fructooligosaccharides or inulin. The highest inulase activity, 0.42 U/ml was detected with the inulin medium and 0.25 U/ml with fructooligosaccharides medium. The cell growth of the isolated strain increased with the amounts of inulin up to 2%(w/v) and maximum production of inulase was found in the cells fed 1% inulin. The inulase of the isolated Bacteroides sp. showed its maximum activity at pH $7.0{\sim}7.5\;and\;50{\sim}50^{\circ}C$ and was found to be an exoinulase judging by its mode of action.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.35-39
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• 2016

To conduct a kinetic study of paraquat (PQ), we investigated 9 patients with acute PQ intoxication. All of them ingested more than 20 ml of undiluted PQ herbicide to commit suicide and arrived at our hospital early, not later than 7 h after PQ ingestion. The urine dithionite test for PQ in all of the nine patients was strongly positive at emergency room. Blood samples were obtained every 30 min for the first 2~3 h and then every 1 or 2 h, as long as the clinical progression was stable among the patients for 30 h after PQ ingestion. The area under the plasma concentration-time curve ($AUC_{inf}$), which was extrapolated to infinity, was calculated using the trapezoidal rule. Toxicokinetic parameters, such as the terminal elimination half-life, apparent oral clearance, and apparent volume of distribution ($V_d/F$) were calculated. The maximum PQ concentration ($C_{max}$) and the time to reach maximum PQ concentration ($T_{max}$) were also obtained. Plasma PQ concentrations in nine patients were well described by a bi-exponential curve with a mean terminal elimination half-life of $13.1{\pm}6.8h$. $C_{max}$ and $AUC_{inf}$ were $20.8{\pm}25.7mg/l$ and $172.5{\pm}160.3h{\cdot}mg/l$, respectively. Apparent volume of distribution and apparent oral clearance were $50.9{\pm}61.3l/kg$ and $173.4{\pm}111.2l/h$, respectively. There were a significant correlation (r=0.84; p<0.05) between the PQ amount ingested and $C_{max}$. $AUC_{inf}$ also showed a significant correlation (r=0.83; p<0.05) with the PQ amount ingested. These correlations provide evidence that PQ has dose-linear toxicokinetic characteristics.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.243-248
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• 2012

In this study, The report analysed the characteristics of power drop and damage of surface in solar cell through high temperature and humidity test. The solar cells were tested during the 1000hr in $85^{\circ}C$ temperature and 85% humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). An analysis of the cell surface through EL(Electroluminescence), the cell has partly change of surface in yearly. Single-crystalline Solar cell efficiency is decreased from 17.7% to 15.6% and decreasing rate is 11.9%. On the other hand, Poly-crystalline Solar cell efficiency is decreased from 15.5% to 14.0% and decreasing rate is 9.3%. A comparison of the fill factor for analysis of electro characteristic in yearly, Single-crystalline Solar cell efficiency is decreased from 78.7% to 78.1% and decreasing rate is 4.7%. On the other hand, Poly-crystalline Solar cell efficiency is decreased from 78.1% to 76.7% and decreasing rate is 1.8%. Single-crystalline has more bigger power drop than poly-crystalline by the silicon purity and silicon atom arrangement. Also, FF decreasing rate has more bigger drop than efficiency decreasing rate for the reason that the damage of surface by exterior environmental factor is the more influence in cell than other reason that is decreasing FF by damage of p-n junction.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.175-184
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• 2012

BACKGROUND: The aim of this study was to isolate and identify algicidal bacterium that tends to kill the toxic dinoflagellate Alexandrium catenella, and to determine the algicidal activity. METHODS AND RESULTS: Among of four algicidal bacteria isolated in this study, NH-12 isolate was the strongest algicidal activity against A. catenella. NH-12 isolate was identified on the basis of biochemical characteristics and analysis of 16S rRNA gene sequences. The isolate showed 97.67% homology with Pseudoalteromonas prydzensis ACAM $620^T$ (U85855), and was designated Pseudoalteromonas sp. NH-12. The optimal culture conditions of this isolate were $25^{\circ}C$, initial pH 8.0, and 3.0% (w/v) NaCl concentration. The algicidal activity of NH-12 was significantly increased to maximum value in the late of logarithmic phase of bacterial culture. As a result of 'cell culture insert' experiment, NH-12 is assumed to produce secondary metabolites, as an indirect attacker. When 10% culture filtrate of NH-12 was applied to A. catenella, over 99% of algal cells were destroyed within 24 h. In addition, the killing effects were increased in dose and time dependent manners. CONCLUSION(S): Taken together, our results suggest that Pseudoalteromonas sp. NH-12 could be a candidate for controlling of toxic algal blooms.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.159-162
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• 2005

전자빔을 이용하던 CRT(Cathode Ray Tube) 모니터에서 픽셀단위의 LCD(Liquid Crystal Display) 디스플레이 사용으로 휴대용 정보처리 장치들은 급속한 발전을 이루게 되었다. 기존의 CRT 모니터에서 전자빔을 사용하던 방식에서 픽셀(Pixel) 단위의 후면발광 디스플레이를 만들면서 CRT 모니터보다 빠른 응답특성을 나타내며 저 전력일 뿐만 아니라 디스플레이의 두께도 줄일 수 있게 되었다. 휴대가 가능한 디스플레이의 발전으로 노트북이나 PDA와 같은 실시간 정보를 활용 및 처리 할 수 있는 방법들을 제시할 수 있었지만 원활한 활용을 위해 더 적은 전력을 사용하는 방법들이 제시되어야 했다. 이에 따라 저 전력 소모, 빠른 응답특성, 넓은 시야각 그리고 경량화가 가능한 디스플레이가 되기 위한 새로운 디스플레이가 선을 보이게 되었다. 현재 차세대 디스플레이로 각광을 받고 있는 디스플레이 소자로는 OLED(Organic Light Emitting Diode)가 있다 이는 LCD 디스플레이가 가지고 있는 단점을 보완하여 우선적으로 높은 색도가 가능하며 후면발광을 사용하지 않고 자체 발광을 하기 때문에 저 전력 소모가 현실화되었다. 또한 디스플레이의 유동성이 가능하여 휘어질 수 있는 특성을 가지고 있다. 그러나 이러한 유기발광 소자의 경우 높은 발광 효율을 위한 구조적 개선이 필요하며 소자의 수명도 개선해야 한다. 이에 따라 유기발광 소자의 메카니즘에 대한 파악이 필요하게 되며 물리적 구조에 대한 이해가 필요하다. 이를 위해 물리적, 수치적 해석으로 소자의 특성을 파악해 줌으로써 개선된 유기발광 소자 제작이 가능 할 것이다.기에 대한 영향정도를 측정하여 정량적으로 도출하였다. 이를 각 구간에 대해 상호 비교 분석함으로써 대형국책사업에서의 공기지연인자에 대한 분석 방법론을 정립하였고 공기지연 분석 방법론의 현실적 적용을 위한 제언과 그에 따른 개선사항에 대해 도출하였다.있는 발판을 마련하게 된다고 추정하였다. 0.5%가 control사이에서 0.95로 가장 색차가 크게 나타났으며, 그 다음이 냉동분쇄 0.5% 0.83으로 나타나 송이의 첨가율이 높을수록 색차가 크게 나타나는 것을 알 수 있다. 색차가 가장 낮은 제품은 법동분쇄 0.3%, 동결건조 0.3%로 나타났다. 송이양갱의 색(color), 냄새(flavor), 맛(taste), 외관(appearances), 질감(viscosity), 종합적 평가(overall acceptability) 등의 관능평가를 실시한 결과 중 색에 대한 기호도는 냉동분쇄 0.1% 송이양갱이 가장 높은 것으로 나타났으나, 집단간 유의한 차이는 나타나지 않았고, 냄새는 동결건조 0.1%의 송이양갱이 3.38로 가장 점수가 높았으며, 냉동분쇄 0.3%의 송이양갱이 2.81로 가장 낮은 기호도를 나타내었다. 맛에서는 p<0.01수준에서 집단간 유의한 차이를 나타내었는데, 동결건조 0.1%가 그 중 가장 높은 기호도를 나타내었으며, 그 다음이 동결건조 0.5%였다. 가장 낮은 선호도를 나타낸 것은 열풍건조 0.5%였다. 질감은 P<.05 수준에서 집단간 유의미한 차이를 나타내었으며 동결건조 0.1%가 가장 높은 기호도를 나타내었으며, 동결건조 0.5%함유 송이양갱이 1.21로서, 현저히 낮은 기호도를 나타내었다. 종합적인 평가에서는 동결건조 0.1%함유

• Journal of Life Science
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• v.27 no.2
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• pp.172-179
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• 2017

The fermentation of Panax ginseng can yield many compounds from ginsenosides that have a wide variety of biological functions. Lactic acid bacteria (LAB) strains are capable of converting ginsenosides. The purposes of this study were to: (1) characterize Enterococcus faecium SA5, an isolated LAB from Mongolian mare milk, (2) identify the existence of extracellular ${\beta}$-glucosidase activity in the milk, and (3) ascertain if the ${\beta}$-glucosidase has the capacity of converting ginsenoside in Korean ginseng. The results revealed that E. faecium SA5 was acid-resistant, bile salt-resistant, and has antibiotic activities against 4 pathogenic microorganisms (Salmonella typhimurium KCTC 3216, Listeria monocytogenes KCTC 3710, Bacillus cereus KCTC 1012, Staphylococcus aureus KCTC 1621). In addition, E. faecium SA5 had tolerance against some antibiotics such as colistin, gentamycin and neomycin. It was also found that E. faecium SA5 possessed bile salt hydrolase activity, which could lower blood cholesterol level. When incubated in 10% (w/v) skim milk as a yogurt starter, E. faecium SA5 caused to decrease pH of the medium as well as increase in viable cell counts. Using TLC and HPLC analysis on the samples incubated in MRS broth, our study confirmed that E. faecium SA5 can produce ${\beta}$-glucosidase, which was capable of converting ginsenoside $Rb_1$ into new ginsenosides $Rg_3-s$ and $Rg_3-r$. It was concluded that E. faecium SA5 possessed a potential of probiotic activity, which could be applied to yogurt manufacture as well as ginsenoside conversion in ginseng.

• Journal of Pharmaceutical Investigation
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• v.26 no.1
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• pp.33-41
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• 1996

In order to study the effect of phenobarbital(PB) on the hepatic transport of diltiazem(DTZ), $Ca^{2+}$ channel blocker, we used isolated hepatocytes of rat which was intraperitoneally pretreated with phenobarbital sodium(75 mg/kg) for four days once a day. For the isolation of rat liver cells, a modification of the two step procedure of Seglen was used. DTZ was dissolved in incubation buffer to the final DTZ concentrations of 200, 400, 600, 800 and 1000 ng/ml in order to elucidate the uptake characteristics of DTZ by hepatocytes. Reactions were stopped at 10, 20, 30, 45, 60, 90, 120 and 300 sec. The initial velocity was determined by disappearance of diltiazem in the hepatocyte suspension. On the other hand, to determine the effect of PB on the in vitro hepatic intrinsic clearance of DTZ we obtained the metabolism rates of DTZ in the control and the PB-pretreated rat hepatocyte at various time intervals. According to pretreatment with PB, the size of hepatocyte and the amount of protein per $10^6$ cells were significantly (p<0.01) increased from $26.92{\pm}0.1364\;m$ to $35.31{\pm}1.00\;m$ and from $468{\pm}6.5\;{\mu}g/10^6$ cells to $628.8{\pm}12.1{\mu}g/10^6$ cells, respectively. In the case or hepatic uptake of diltiazem, $K_m$ was not different in the normalization by cell numbers and increased from $2.90\;{\mu}M\;to\;13.89\;{\mu}M$ in the normalization by protein amount. $V_max$ was increased regardless of normalization by protein amount and cell numbers, from $1.21\;{\mu}mole/min \;{\cdot}\;mg\;protein\;to\;3.96\;{\mu}mole/min\;{\cdot}\;mg\;protein\;and\;from\;2.38\;{\mu}mole/min\;{\cdot}\;10^6\;cells\;to\;2.83\;{\mu}mole/min\;{\cdot}\;10^6\;cells$, respectively. The in vitro hepatic intrinsic clearance of DTZ was significantly (p<0.01) increased from $0.640{\pm}0.038\;ml/mim\;{\cdot}\;10^6\;cells\;to\;2.385{\pm}0.212\;ml/min\;{\cdot}\;10^6\;cells$ due to PB-pretreatment. These results suggest that the uptake of DTZ by hepatocyte is extremely fast and PB enhances the hepatic intrinsic metabolic clearance of DTZ.