• 미생물학회지
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• 제41권2호
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• pp.146-151
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• 2005

전분 이용이 가능한 산업용 Saccharomyces cerevisiae균주를 개발하기 위해 alcohol dehydrogenase 유전자 프로모터(ADClp)의 조절하에 발현되는 Aspergillus awamori glucoamylase cDNA 유전자(GA1)를 산업용 S. cerevisiae의 염색체에 도입하였다. 산업적 이용에 적합한 효모균주를 얻기 위해 세균 ampicillin 저항성 유전자가 제거되고 GA1 유전자와 선별 표지유전자로 S. cerevisiae aureobasidin A 저항성 유전자(AUR1-C)와 재조합 부위로 Tyretrotransposon $\delta$-서열이 포함된 integrative cassette를제조하였다. 이 $\delta-integrative$ cassette로 형질전환된 산업용 S. cerevisiae는 배지상에 glucoamylase를 생산 분비하였고 전환을 유일한 탄소원으로 하여 생장하였다. 형질전환체를 비선택배지에서 배양했을 매 삽입된 GA1유전자가 100세대까지 안정되게 유지되었다.

• 미생물학회지
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• 제28권3호
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• pp.181-187
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• 1990

전분 분해능력을 갖는 알콜생산용 효모를 만들기 위해 Saccharomyces cerevisiae에 glucoamylase 유전자인 STA를 도입하였다. 도입된 형질의 발현증대를 위해 STA 유전자의 promoter 부위를 alcohol dehydrogenase isoenzyme I 유전자의 promoter 부위와 치환 시켜준 재조합 플라스미드를 재조하였으며 안정성을 증진시키기 위해 centrometer 부위를 치환시킨 결과 glucoamylase의 발현이 증가하였으며, STA 유전자와 centromere를 갖고 있는 재조합 플라스미드는 여러세대가 거듭되어도 비교적 안정하게 유지되었으나 낮은 copy 수로 인해 형질전환체의 효소 역가와 형질전환 빈도는 낮아졌다. STA 유전자가 도입되어 형질전환된 다배체 산업용 효모는 액화 과정만을 거친 주정생산 배지(액화액)에서 원래의 알콜 생산용 효모에 비해 훨씬 많은 양의 알콜을 생산해 내었다. 그러나 centromere를 보유하는 플라스미드에의한 산업용 효모의 형질전환에는 실패하였다.

• 한국미생물·생명공학회지
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• 제25권3호
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• pp.266-270
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• 1997

From persimmon fruits, about 40 yeast strains were isolated and tested for their ability of alcohol fermentation were tested. Among them, two strains, RCY14 and RCY15, showing the highest alcohol fermentibility were selected for further investigations. They were identified as Saccharomyces cerevisiae and Saccharomyces kluyveri based on their morphological, cultural and physiological properties. Their optimum condition for the alcohol fermentation in YPD-15% glucose was pH 6.0, 30$circ$C and 120 rpm of shaking speed. The alcohol yields of S. cerevisiae RCY14 and S. kluyveri RCY15 in a persimmon juice were 94.54 and 96.81%, respectively. Although the alcohol yields of both strains were not very high in YPD-15% glucose, they were much higher in a persimmon juice as compared to those of S. cerevisiae Balyon-1, S. cerevisiae 701 and S. cerevisiaein W3 which are being used in the industrial alcohol fermentation.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1240-1249
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• 2005

Saccharomyces cerevisiae KNU5377 has potential as an industrial strain that can ferment wasted paper for fuel ethanol at $40^{\circ}C$ [15, 16]. To understand the characteristics of the strain, genome-wide expression was performed using DNA microarray technology. We compared the homology of the DNA microarray between genomic DNAs of S. cerevisiae KNU5377 and a control strain, S. cerevisiae S288C. Approximately $97\%$ of the genes in S. cerevisiae KNU5377 were identified with those of the reference strain. YHR053c (CUP1), YLR155c (ASP3), and YDR038c (ENA5) showed lower homology than those of S. cerevisiae S288C. In particular, the differences in the regions of YHR053c and YLR155c were confirmed by Southern hybridization, but did not with that of the region of YDR038c. The expression level of mRNA in S. cerevisiae KNU5377 and S288C was also compared: the 550 ORFs of S. cerevisiae KNU5377 showed more than two-fold higher intensity than those of S. cerevisiae S288C. Among the 550 ORFs, 59 ORFs belonged to the groups of ribosomal proteins and mitochondrial ribosomal proteins, and 200 ORFs belonged to the group of cellular organization. DIP5 and GAP1 were the most highly expressed genes. These results suggest that upregulated DIP5 and GAP 1 might take the place of ASP3 and, additionally, the sensitivity against copper might be contributable to the lowest expression level of copper-binding metallothioneins encoded by CUP 1a (YHR053c) and CUP1b (YHR055c) in S. cerevisiae KNU5377.

• KSBB Journal
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• 제26권5호
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• pp.439-442
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• 2011

1,2-propanediol (1,2-PD) is a commodity chemical that is currently produced from petrochemical derivatives. Saccharomyces cerevisiae is well characterized and a successful industrial microorganism to enable the improvement of the 1,2-propanediol production by metabolic engineering. A recombinant S. cerevisiae M3G3 was used to produce 1,2-propanediol. S. cerevisiae M3G3 is the diploid strain that contains 3 copies of mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase). S. cerevisiae M3G3 was cultivated at various culture conditions by changing culture temperature, glucose concentration, and inducer concentration. Also the effect of induction time was studied to optimize the production of 1,2-propanediol. Batch and fed-batch cultivation of S. cerevisiae M3G3 was performed by using a 5 L jar fermenter. The highest concentration of 1,2-propanediol in batch cultivation was 0.86 g/L and it was further improved to 1.33 g/L in fed-batch cultivation.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.447-450
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• 2005

Aspergillus niger inuE gene and Kluyveromyces marxianus INUI gene coding for exoinulinase were expressed in Saccharomyces cerevisiae under the control of K. marxianus INUI promoter. Recombinant S. cerevisiae expressing K. marxianus exoinulinase produced maximum 85 U/ml into culture medium, which was 9- to 14-fold higher than the activity produced by any other strain reported so far. In addition, K. marxianus INUI promoter produced 20- fold higher activity than S. cerevisiae glyceraldehydes phosphate dehydrogenase (GPD) promoter in S. cerevisiae.

• 미생물학회지
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• 제44권3호
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• pp.264-269
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• 2008

$\beta$-Amylase를 생산하여 전분 분해능을 갖는 산업용 효모를 개발하기 위해 산업용 Saccharomyces cerevisiae에서 Achlya bisexualis $\beta$-amylase (BAMY)유전자를 ADC1 promoter에 연결하여 구성적으로 발현시켰다. 효모의 형질전환은 $\delta$-서열을 재조합 부위로 하는integration 시스템을 이용하였다. Integration 시스템의 세균 유전자 부분은 제거되고 BAMY 유전자와 $\delta$-서열을 갖고 있는 짧은integrative cassette를 제조하였다. BAMY 유전자를 발현하는 재조합 S. cerevisiae 형질전환체는 세포외 배지로 45 kDa의 $\beta$-amylase를 분비하였고, $\beta$-amylase 활성은 A. bisexualis에 비해 약 18.5배 높았다. 형질전환체에 다중도입된 BAMY 유전자는 비선택배지에서 100세대 생장 후에도 안정되게 유지되었다. 각종전분을 기질로 했을 매 $\beta$-amylase의 활성은soluble starch를 기질로 했을 경우와 유사하게 높았고, 가수분해산물 분석 결과 maltose가 주 분해산물이었다.

• KSBB Journal
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• 제26권5호
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• pp.427-432
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• 2011

In this study, a EXGA gene code for exo-β-1,3-glucanase from Aspergillus oryzae was overexpressed and secretory produced in Saccharomyces cerevisiae. To overexpress the β-1,3-glucanase, pGInu-exgA and pAInu-exgA plasmids having GAL10 and ADH1 promoter, respectively, and exoinulinase signal sequence (Inu s.s) were constructed and introduced in S. cerevisiae SEY2102 and 2805. The recombinant β-1,3-glucanase was successfully expressed and secreted into the medium and the β--1,3-glucanase activity in 2102/pGInu-exgA and 2102/pAInu-exgA strain were 5.01 unit/mL and 4.09 unit/mL, respectively. In the 2805/pGInu-exgA and 2805/pAInu-exgA strain, the β-1,3-glucanase activity showed 3.23 unit/mL and 3.22 unit/mL, respectively. Secretory efficiency in each strain reached 95% to 98%. Subsequently, the recombinant β1,3-glucanase was used for ethanol production. Ethanol productivity in 2102/pAInu-exgA strain was 0.83 g/L when pre-treated Laminaria japonica which has initial reducing sugar of 1.4 g/L was used as substrate. It is assumed that the polysaccharides of Laminaria japonica was effectively saccharified by recombinant β-1,3-glucanase, resulting in increase of ethanol productivity. These results suggested that recombinant β-1,3-glucanase was efficiently overexpressed and secreted in S. cerevisiae SEY2102 as host strain by using ADH1 promoter-Inu s.s system.

• 한국미생물·생명공학회지
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• 제32권4호
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• pp.356-361
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• 2004

The ethionine resisconferring gene (ERCI) was constitutively expressed under the control of the alcohol dehydrogenase gene promoter (ADClp) and introduced into the chromosomes of an industrial polyploid strain of Saccharocerevisiae by using the 8-sequences of the Tyl retrotransposon as the recombination site. 8-Integrative cassette devoid of bacterial DNA sequences containing the ampicillin resistance gene was constructed that had the aureobasidin A resistance gene (AURl-C) as the selection marker and ERCl gene. The ERCl gene was also employed as the selection marker in the 8-integrative cassette lacking the A URl-C gene. Industrial Saccerevisiae transformed with these integrative cassettes exhibited strong resistance to DL-ethioncompared with nontransformants.

• Mycobiology
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• 제38권4호
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• pp.302-309
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• 2010

Formic acid is a representative carboxylic acid that inhibits bacterial cell growth, and thus it is generally considered to constitute an obstacle to the reuse of renewable biomass. In this study, Saccharomyces cerevisiae was used to elucidate changes in protein levels in response to formic acid. Fifty-seven differentially expressed proteins in response to formic acid toxicity in S. cerevisiae were identified by 1D-PAGE and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analyses. Among the 28 proteins increased in expression, four were involved in the MAP kinase signal transduction pathway and one in the oxidative stress-induced pathway. A dramatic increase was observed in the number of ion transporters related to maintenance of acid-base balance. Regarding the 29 proteins decreased in expression, they were found to participate in transcription during cell division. Heat shock protein 70, glutathione reductase, and cytochrome c oxidase were measured by LC-MS/MS analysis. Taken together, the inhibitory action of formic acid on S. cerevisiae cells might disrupt the acidbase balance across the cell membrane and generate oxidative stress, leading to repressed cell division and death. S. cerevisiae also induced expression of ion transporters, which may be required to maintain the acid-base balance when yeast cells are exposed to high concentrations of formic acid in growth medium.