• Title/Summary/Keyword: sEH

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A Study on Engineering Education based on Cooperation between University and Enterprises (산학협력기반 공학교육모델에 관한 연구)

  • Park, Cheol-Woo
    • Journal of Engineering Education Research
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    • v.11 no.4
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    • pp.5-10
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    • 2008
  • Conventional engineering education models have fallen to give satisfactory results to enterprises. So this paper deals with the new engineering education system, Engineering House, to overcome it. EH is made of three spaces and three concepts. Concept means system. Three concepts are things about a education program, a research cooperation, a open-door policy of EH facilities. First of all, Education system for undergraduates is most important of all. We intend to give them chances for real engineering experiences. Specialist from companies are participated in the education. The second is a research network. EH is managed by two or three professors together and their researches are carry out with companies's researcher. Key-point is doing all together. The third is service system for regional enterprises. EH's facilities are opened. Our students and professors are supporting directly. Mainly high price measuring machine is used. Like these, networks with companies are very helpable for undergraduate's educations and job connections. These are the work based learning system. Engineering House system look forward to getting to good program for undergraduate, based on the co-operation between university and enterprises.

Optimization of the Reaction Conditions for (R)-Phenyl-1,2-ethanediol Preparation by Recombinant Epoxide Hydrolase from Caulobacter crescentus (재조합 Caulobacter crescentus 에폭사이드 가수분해효소를 이용한 광학활성 Diol 제조 조건의 최적화)

  • Lee, Ok-Kyung;Kim, Hee-Sook
    • Microbiology and Biotechnology Letters
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    • v.35 no.4
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    • pp.285-291
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    • 2007
  • Enantioconvergent hydrolysis process for the preparation of chiral diol from racemic epoxides by using the recombinant Caulobacter crescentus epoxide hydrolase (CcEH) in Escherichia coli BL21 (DE3) was optimized. For the optimization, the effects of detergent, temperature and product inhibition on the enantiopurity and the yield of diol were investigated. (R)-phenyl-1,2-ethanediol with 92% enantiomeric excess and 56% yield from 20 mM racemic styrene oxide was obtained by using the recombinant CcEH at the optimal condition of $10^{\circ}C$ and the addition of 2% (w/v) Tween 80. At 50 mM racemic styrene oxide was used as a substrate, (R)-phenyl-1,2-ethanediol was obtained with 87% enantiomeric excess and 77% yield. Racemic phenyl-1,2-ethanediol, (R)-phenyl-1,2-ethanediol and (S)-phenyl-1,2-ethanediol dramatically inhibited the hydrolytic activity of the recombinant CcEH. These results suggested that another EH with the regioselectivity on ${\beta}$-position of (R)-enantiomer and without feedback inhibition by products would be needed as the partner EH of C. crescentus EH.

Study on Spatial Characteristics of Physicochemical Components of Spring Water in Mts. Geumjeong and Baekyang Area Using Kriging (크리깅 기법을 이용한 금정산-백양산 일대 용천수의 물리화학적 성분의 공간적 분포 특성 연구)

  • 함세영;정재열;류상민;강래수
    • The Journal of Engineering Geology
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    • v.12 no.4
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    • pp.439-457
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    • 2002
  • Sping waters at 60 sites and groundwaters at 6 wells in Mts. Geumjeong and Baekyang area were investigated for measuring nine physicochemical components (temperature, pH, Eh, EC, TDS, DO, salinity, alkalinity and discharge rate). The pH of spring waters ranges from 5.06 to 8.38, alkalinity from 7.93 to 102.21 mg/ㅣ, electrical conductance from 9.5 to $270{\;}\mu\textrm{s}/cm$, Eh from 64.2 to 685.9 mV, DO from 4.57 to 12.13 mg/l, and the discharge rate from 4.26 to 182.2 ml/s. General statistics was carried out to analyze statistical characteristics of those components. To compare the components with one another, regression analyses were carried out. And the components of spring waters were compared to those of groundwaters. Kriging was used to estimate the spatial variation of DO, pH, Eh, EC, alkalinity and discharge rate in the study area. The kriged isopleth maps were made using normalized kriged values to find anomalies of the physicochemical components and to compare anomalies of different components.

Development of Detection Method of Unapproved Genetically Modified Potato (EH92-527-1) in Korea using Duplex Polymerase Chain Reaction (Duplex PCR을 이용한 국내 미승인 유전자변형 감자(EH92-527-1)의 검사법 개발)

  • Yoo, Myung-Ryul;Kim, Jae-Hwan;Yea, Mi-Chi;Kim, Hae-Yeong
    • Korean Journal of Food Science and Technology
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    • v.45 no.2
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    • pp.156-160
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    • 2013
  • A duplex polymerase chain reaction (PCR) method was developed to detect unapproved genetically modified (GM) potato (EH92-527-1) in Korea. The UDP-glucose pyrophosphorylase (UGP) gene was selected as an endogenous reference gene for potato and used to validate the specificity for 14 different crops. The primer pair EH92-F/R was designed to amplify the junction sequence between the genome and transgenic region introduced in GM potato. Its specificity was also validated using several different GM events. The detection limit of the duplex PCR method is approximately 0.05%. This duplex PCR method could be useful for monitoring cultivation of unauthorized GM potato in Korea.

Development of Recombinant Saccharomyces cerevisiae Expressing Epoxide Hydrolase for the Preparation of Chiral Phenyl Oxirane (광학활성 Phenyl Oxirane 제조용 유전자 재조합 생촉매 개발)

  • 이수정;이은정;김초희;이지원;김희숙;이은열
    • Journal of Life Science
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    • v.13 no.1
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    • pp.105-109
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    • 2003
  • Epoxide hydrolase (EH) gene from Aspergillus niger #33 was cloned from cDNA library generated by reverse transcriptase-polymerase chain reaction (RT-PCR). The nucleotide sequence analysis revealed that the deduced amino acid sequence was almost similiar to that of A. niger LCP521 previously reported. The cloned EH gene was transformed into Saccharomyces cerevisiae and expressed by addition of galactose. The recombinant S. cerevisiae showed hydrolytic activity toward racemic phenyl oxirane substrate based on chiral GC analysis, and can be used as a potential biocatalyst for the preparation of chiral phenyl oxirane.

Enhanced Heterologous Expression of Aspergillus niger Epoxide Hydrolase and Its Application to Enantioselective Hydrolysis of Racemic Epoxides (Aspergillus niger의 Epoxide Hydrolase 고효율 발현 및 라세믹 에폭사이드의 입체선택적 가수분해)

  • Lee, Soo Jung;Kim, Hee Sook;Lee, Eun Yeol
    • Applied Chemistry for Engineering
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    • v.17 no.5
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    • pp.557-560
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    • 2006
  • The epoxide hydrolase (EH) of Aspergillus niger LK was expressed to high levels in Escherichia coli based on codon usage. E. coli, Rosetta (DE3)PLysS, containing a large number of tRNAs for rare-codons was employed as a host strain. The recombinant E. coli expressing A. niger EH showed an enhanced enantioselective hydrolysis activity toward racemic styrene oxide. Enantiopure (S)-styrene oxide with a high enantiopurity of 99% ee was obtained from racemic substrates.

Bioinformatics based Identification and Characterization of Epoxide Hydrolase of Gordonia westfalica for the Production of Chiral Epoxides (Bioinformatics를 활용한 토양미생물인 Gordonia westfalica Epoxide Hydrolase 생촉매 개발 및 Chiral Epoxides 제조 특성 분석)

  • Lee Soo Jung;Lee Eun Jung;Kim Hee Sook;Lee Eun Yeol
    • KSBB Journal
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    • v.20 no.4
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    • pp.311-316
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    • 2005
  • Epoxide hydrolases (EHs) are versatile biocatalysts for the preparation of chiral epoxides by enantioselective hydrolysis from racemic epoxides. Various microorganisms were identified to possess a EH activity by multiple sequence alignment and analysis of conserved domain sequence from genomic and megaplasmid sequence data. We successfully isolated Gordonia westfalica possessing EH activity from various microbial strains from culture type collections. G. westfalica exhibited (R)-styrene oxide preferred enantioselective hydrolysis activity. Chiral (S)-styrene oxide with high optical purity $(>\;99\%)\;ee)$ and yield of $36.5\%$ was obtained from its racemate using whole-cell of G. westfalica.

Enantioselective Hydrolysis for Preparing (S)-Styrene Oxide in Organic Solvents Using Recombinant Escherichia coli Expressing Protein-engineered Epoxide Hydrolase of Mugil cephalus (Mugil cephalus 유래 에폭사이드 가수분해효소를 발현하는 재조합 대장균을 이용한 유기용매에서의 (S)-Styrene Oxide 제조를 위한 입체선택적 가수분해 반응)

  • Lee, Ok Kyung;Lee, Eun Yeol
    • Applied Chemistry for Engineering
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    • v.23 no.6
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    • pp.599-603
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    • 2012
  • The enantioselective hydrolysis of racemic styrene oxide in organic solvents was conducted using a recombinant E. coli expressing protein-engineered Mugil cephalus epoxide hydrolase (McEH). The volumetric total activity of the recombinant E. coli was enhanced 2.2-fold by IPTG induction at a mid-exponential growth phase. Among organic solvents with different log P values, isooctane was chosen based on the high activity and the enantioselectivity of McEH. Some lyoprotectants such as skim milk or sucrose enhanced the McEH activity. Enantiopure (S)-Styrene oxide with a 98% ee was obtained from the racemic styrene oxide with a 53.6% yield based on its theoretical yield in isooctane.

Comparative Evaluation of Some Selected Sediment Transport Formulas (하천 유사량 공식들의 비교평가)

  • Yu, Kwone Kyu;Woo, Hyo Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.4
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    • pp.67-75
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    • 1990
  • Performances of a total of 6 selected sediment transport formulas including Engelund & Hansen(EH)'s, Ackers & White(AW)'s, Yang(YN)'s, Brownlie(BR)'s, Karim & Kennedy (KK)'s, and Rijn(RJ)'s ones, which have been known to be relatively reliable, were tested using the 1,399 measured sediment discharge data points of the 20 rivers selected from Brownlie's compendium of sediment discharge. The calculated results were plotted with the input parameters such as the unit discharge, mean velocity, flow depth, energy slope, and median diameter respectively, and trend of each formula's performance was analyzed. These analyses revealed that, in general, EH's and RJ's formulas are more reliable, BR's, AW's, and KK's ones are moderately reliable, and YN's one is less reliable. AW's formula drastically overestimates sediment discharge for fine sediment(D<0.15mm), and YN's one under-estimates sediment discharge for streams with large water discharge(q>5 cms/m).

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