• 제목/요약/키워드: URA

검색결과 96건 처리시간 0.036초

$\alpha$-Amylase와 Glucoamylase를 동시에 분비하는 배수체 재조합효모에 의한 전분기질로 부터의 에탄올 생산

  • 박선영;김민수;김근
    • 한국미생물·생명공학회지
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    • 제24권5호
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    • pp.604-612
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    • 1996
  • To improve the fermentation characteristics of the haploid starch-fermenting recombinant yeast strain K114/YIpMS$\Delta$R(LEU2/URA3) secreting both $\alpha$-amylase and glucoamylase was rare-mated with polyploid industrial yeast Saccharomyces sp. K35. The K35 strain had good fermentation-characteristics such as ethanol-tolerance, high temperature and sugar-tolerance, and high fermentation rate. Among the resulting 66 hybrids, the best strain RH51 was selected. The RH51 exhibited amylolytic activity of K114/YIpMS$\Delta$R(LEU2/URA3) as well as ethanol and sugar tolerance of K35. The optimum temperature of hybrid RH51 for starch fermentation was 34$\circ$C which was same as that of K35 but different from that (30$\circ$C) of K114/YIpMS$\Delta$R(LEU2/URA3). The optimum pH was 5.0. The optimum size of inoculum was 2% as the pellet (w/v) of yeast cells. The hybrid strain RH51 produced 7.0% ethanol (w/v) from 20% (w/v) soluble starch while K35 formed almost no ethanol, 0.3% (w/v). RH51 strain produced 7.5% (w/v) ethanol after 8 days in a 2.5 l fermenter containing 800 ml of 20% (w/v) soluble starch. The residual starch content in the fermentation medium was 1.68% (w/v), and therefore almost all the starch was fermented completely.

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Target DNA 염기서열 내에 존재하는 비상동성 간격이 상동성재조합을 이용한 클로닝 빈도에 미치는 영향 (Effect of Non-homologous Spacing in Target DNA Sequence on the Frequency of Cloning Based Homologous Recombination)

  • 김재우;도은주;윤세련;정윤희;윤영호;임선희;선우양일;박인호
    • 미생물학회지
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    • 제41권4호
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    • pp.239-245
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    • 2005
  • Transformation-associated recombination (TAR) 클로닝 법은 복잡한 게놈으로부터 염색체 내의 특정부위나 유전자를 선택적으로 분리할 수 있다. 이 방법은 목적 유전자에 근접한 작은 게놈DNA 염기서열 정보를 필요로 한다. 이 기술은 효모의 spheroplast transformation을 시키는 동안 목적으로 하는 유전자의 5' 또는 3' 서열을 포함하고 있는 TAR vector와 게놈DNA사이에서 일어나는 상동성재조합에 의해 이루어진다. 본 연구에서는 plasmid 모델시스템을 이용하여 target hooks 내에 존재하는 비상동성 염기서 열이 상동성재조합에 미치는 영향을 조사하였다. plasmid에 존재하는HIS3유전자와 변형시킨 his3-TRP1-his3 단편 사이의 상동성재조합의 효율은 $Ura^+$ 형질전환체의 형질분석에 의해 이루어졌다. $Ura^+$ 형질전환체의 수는 7종류의 서로 달리 변형된 his3-TRP1-his3 단편들을 사용하였을 매 거의 동일하게 나타났다. 그러나 $Trp^+His^+$ positive recombinants의 빈도는 변형된 his3-TRP1-his3 단편 내에 비상동성 영역에 부정확한 간격을 지닐 때 현저한 감소를 나타내었다. 이러한 결과로서, 부정확한 간격이 target hook과 substrate DNA 사이에 일어나는 상동성재조합을 방해하는 것으로 사료된다. 그러므로 이종간의 상동유전자를 클로닝 할 때에는 target hook내의 비상동성 염기서열이 존재한다면 이것이 정확한 간격을 지니는지 여부를 중요란 요인으로 고려해야 한다.

Assessment of Public Engagement Approach in Various Project Stages: The Case Study of Central Market, Hong Kong

  • Wong, Crystal;Chan, Icy;Lam, Lily;Zayed, Tarek;Sun, Yi
    • 국제학술발표논문집
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    • The 8th International Conference on Construction Engineering and Project Management
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    • pp.267-277
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    • 2020
  • The present research evaluates the public engagement approach in various project stages. Hong Kong had long been criticized as top-down and executive-led jurisdiction by overlooking the importance of cultural heritage and public concerns on public projects. It was suggested to the government to engage public and provide sufficient public consultation. Thereby, the government announced a series of revitalization and conversion measures in Policy Address in 2008. To carry out the measures, there were voices, because of diverse and sometimes conflicting interests, over the effect of revitalization project. On the other hand, studies reveal that there are benefits of revitalization and enhancement of public engagement approach. In pursuit of the subject, the present research aims at studying the Central Market as a case study pilot project. In October 2009, the Policy Address announced that the Central Market be revitalized. Tasked to implement the project, Urban Renewal Authority (URA) continued to adopt the people-oriented approach as the guiding principle in its core business and in heritage preservation and revitalization so as to create a sustainable development. Between government and the public, URA acts as a bridge for communication. As between URA and the public, URA conducted public consultation, set up an ad-hoc committee in January 2016 to be in charge of the project and will continuously inform the government and public with the updates and project progress. The main objectives of the present research are to assess the advantages and challenges in different stages of public engagement approach, to evaluate the engagement system, to give a comprehensive view for participation of stakeholders, and to find out effective strategies to enhance civil engagement. Research was achieved through interviews to key persons in the project, questionnaire that was distributed to community and experts in the field. Case Study of the Central Market was studied and investigated using different sources, such as newspapers, journals, etc, to evaluate the degree of public engagement in the project. Both detailed qualitative methodological approaches of interview, questionnaire, and case study, act as a synergy to demonstrate the research objectives and provide the comprehensive perceptions on the revitalization project. The results show that public participants in revitalized project have generated considerable value enhancements to social-cultural, environmental, political and economic aspect. This study provides valuable insights that the public participation can make positive contribution to sustainability in the city. The findings indicate that no any single system is flawless therefore seeking both public opinions and professional advices are also important as a comprehensive approach to achieve higher sustainability of the building.

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국가공역체계 내에서 군용 무인항공기 비행규칙에 관한 제언 (A Proposal on the Aviation Rules of the Military UAV in the National Airspace System)

  • 박원태;이강석;임광현
    • 한국항공운항학회지
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    • 제22권1호
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    • pp.22-31
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    • 2014
  • Military UAV(Unmanned Aerial Vehicle) operated as a RC(Remotely Control) model level within the limit of the military special use airspace until now. However, the high and medium altitude of URA(Unmanned Reconnaissance Aircraft) which the ROKAF have been trying to import recently is at the UAV level and needs the criteria for the classified airspace flights. The required flight criteria includes operator location, mission operation limit, equipment, etc., which are the principle and standard applied based on the airspace use for UAV. Also, the general flight rules, visual flight rules, instrument flight rules are required in order to have to be applied to the actual flight. Besides, an appliance regulation needs to be arranged regarding two-way communication, ATC and communication issue, airspace and area in-flight between UAS( Unmanned Aircraft System) users. An operation of the UAV in the air significantly requires the guarantee of the aircraft's capacity, and also the standardized flight criteria. A safe and smooth use is ensured only if this criteria is applied and understood by the entire airspace users. For the purpose, a standardized military UAV flight operations criteria that is to be applied for each airspace by UAV is to be prepared through analysis of the present state, a legend UAV system, and a special character analysis.

Quantifiable Downregulation of Endogenous Genes in Agaricus bisporus Mediated by Expression of RNA Hairpins

  • Costa, Ana S.M.B.;Thomas, D. John I.;Eastwood, Daniel;Cutler, Simon B.;Bailey, Andy M.;Foster, Gary D.;Mills, Peter R.;Challen, Michael P.
    • Journal of Microbiology and Biotechnology
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    • 제19권3호
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    • pp.271-276
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    • 2009
  • Functional gene studies in the cultivated white button mushroom Agaricus bisporus have been constrained by the absence of effective gene-silencing tools. Using two endogenous genes from A. bisporus, we have tested the utility of dsRNA hairpin constructs to mediate downregulation of specific genes. Hairpin constructs for genes encoding orotidine 5'-monophosphate decarboxylase (URA3) and carboxin resistance (CBX) were introduced into A. bisporus using Agrobacteriummediated transfection. Although predicted changes in phenotype were not observed in vitro, quantitative-PCR analyses indicated unambiguously that transcripts in several transformants were substantially reduced compared with the non-transformed controls. Interestingly, some hairpin transformants exhibited increased transcription of target genes. Our observations show that hairpin transgenic sequences can mediate downregulation of A. bisporus endogenous genes and that the technology has the potential to expedite functional genomics of the mushroom.

Yarrowia lipolytica의 Multicopy Integration Vector 개발 (Development of a Multicopy Integration Vector in Yarrowia lipolytica)

  • 김정윤;우문희
    • 한국미생물·생명공학회지
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    • 제23권5호
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    • pp.536-543
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    • 1995
  • Multicopy integration vector is a very useful vector system in that they can be integrated into chromosomal DNA in several copies and stably maintained under non-selective conditions. To develop a multicopy integration vector system in the yeast Yarrowia lipolytica, P-type ribosomal DNA was cloned from Y lipolytica. A HindIII-BglII fragment of the cloned rDNA and a promoterless URA3 gene were inserted into pGEM1, generating multicopy integration vectors, pMIYL-1 and pMIYL-2. The rDNA fragment is for targeted homologous recombination between the vector and the chromosomal DNA of Y. lipolytica, and the promoterless URA3 gene is a defective selection marker for inducing multicopy integration. pMIYL-1 and pMIYL-2 have an unique restriction enzyme site, KpnI, and two unique restriction enzyme sites, KpnI and EcoRI, repectively, which can be used for targeting of the vectors into the rDNA of Y. lipolytica chromosomal DNA. After transformation of the vectors into Y. lipolytica, copy number and stability were analyzed by Southern hybridization. The vectors were found to be present in less than 5 copies per cell and were stably maintained during growth in non-selective media.

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Cloning of Genomic DNAs of Trametes versicolor Acting as Autonomously Replicating Sequences in Saccharomyces cerevisiae

  • Sora An;Park, Kyoung-Phil;Park, Hyoung-Tae;Kim, Kyu-Joong;Kim, Kyunghoon
    • Journal of Microbiology
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    • 제40권3호
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    • pp.245-247
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    • 2002
  • A genomic DNA library of the fungus Trametes versicolor was constructed in a yeast integration vector which contains the URA3 gene of the budding yeast Saccharomyces cerevisiae and the gene responsible for hygromycin B resistance, and fragments acting as autonomously replicating sequences (ARSes) in the budding yeast were identified from the genomic DNA library. Sixteen recombinant plasmids from the library transformed the budding yeast Saccharomyces cerevisiae to Ura+ at high frequencies. They were maintained stably under selective conditions, but were gradually lost from yeast cells at different rates under nonselective conditions, indicating that they contain eukaryotic origins of DNA replication and exist as extrachromosomal plasmids. Base sequences of four ARS DNAs among the 16 cloned fragments revealed that all or the four contain at least one 11 bp [(A/T)TTTA(T/C)(A/G)TTT(A/T)]consensus sequence of the budding yeast ARS.