• 에너지공학
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• 제15권2호
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• pp.118-126
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• 2006

미생물을 이용하여 수소를 생산하는 기술은 광합성 작용에 의한 직간접 물분해, 광합성 발효, 혐기발효, 균체외 반응 등 여러 가지 기술이 있으며 본 논문에서는 이들의 적용되는 미생물과 수소생산 메커니즘을 중심으로 소개하였다. 동시에 본 기술들의 현재까지 개발된 사례를 선진국과 국내 현황을 중심으로 기술하였다. 생물학적으로 수소를 생산하는 기술은 1940년대 후반부터 실험실적인 연구가 시작되었으나, 1990년대 환경문제를 해결하기 위해서 전 세계적으로 연구가 다시 활성화되었으며, 이 글에서는 미국, 일본, 유럽연합 및 한국을 중심으로 국내외 연구현황을 소개하였다.

• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.1982-1991
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• 2018

Ethanol accumulation inhibited the growth of Saccharomyces cerevisiae during wine fermentation. Autophagy and the release of reactive oxygen species (ROS) were also induced under ethanol stress. However, the relation between autophagy and ethanol stress was still unclear. In this study, expression of the autophagy genes ATG1 and ATG8 and the production of ROS under ethanol treatment in yeast were measured. The results showed that ethanol stress very significantly induced expression of the ATG1 and ATG8 genes and the production of hydrogen peroxide ($H_2O_2$) and superoxide anion (${O_2}^{{\cdot}_-}$). Moreover, the atg1 and atg8 mutants aggregated more $H_2O_2$ and ${O_2}^{{\cdot}_-}$ than the wild-type yeast. In addition, inhibitors of the ROS scavenging enzyme induced expression of the ATG1 and ATG8 genes by increasing the levels of $H_2O_2$ and ${O_2}^{{\cdot}_-}$. In contrast, glutathione (GSH) and N-acetylcystine (NAC) decreased ATG1 and ATG8 expression by reducing $H_2O_2$ and ${O_2}^{{\cdot}_-}$ production. Rapamycin and 3-methyladenine also caused an obvious change in autophagy levels and simultaneously altered the release of $H_2O_2$ and ${O_2}^{{\cdot}_-}$. Finally, inhibitors of the mitochondrial electron transport chain (mtETC) increased the production of $H_2O_2$ and ${O_2}^{{\cdot}_-}$ and also promoted expression levels of the ATG1 and ATG8 genes. In conclusion, ethanol stress induced autophagy which was regulated by $H_2O_2$ and ${O_2}^{{\cdot}_-}$ derived from mtETC, and in turn, the autophagy contributed to the elimination $H_2O_2$ and ${O_2}^{{\cdot}_-}$.

• Applied Biological Chemistry
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• 제40권1호
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• pp.58-64
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• 1997

카이이케호에서 농밀하게 분포하는 Chromatium sp.의 수소생산을 몇몇 환경조건하에서 측정하였다. 최대수소생산 ($0.01\;{\mu}mol/hr/(mg\;dry\;cell\;weight)$)은 낮은 조도 (1000 lux), 20 mg HS-S/l의 황화수소 농도와 $30^{\circ}C$의 조건하에서 얻을 수 있었다. 수소생산은 질소가스 또는 암모늄에 의해 상당히 저해를 받았다. Chromatium sp.의 수소생산속도는 타 광합성세균에 비해 낮았다. 본 균은 광독립영양적으로 낮은 조도 또는 낮은 $H_2S$ 농도하에서도 쉽게 수소를 생산하는 점으로부터 카이이케흐의 가장 유력한 수소생산자라고 고려되었다. 이러한 Chromatium sp.의 광독립영양적 수소생산특성으로부터, 본 광합성세균은 온대역에서의 생물적 수소생산시스템에 대한 경제적 이고 실용적인 생물종이 될 수 있으리라 제안되었다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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• pp.101-104
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• 2004

Among biological hydrogen production processes, fermentative processes have some advantages. In this research, the hydrogen producing bacterium was isolated from domestic landfill area and identified as Enterobacter sp. The strain was named Enterobacter sp. SNU-1453. Important parameters for the hydrogen process include pH, temperature, concentration of initial glucose, and kind of sugars. The pH of the culture medium significantly decreased as fermentation proceeded due to the accumulation of various organic acids, and this inhibited the $H_2$ production seriously. When pH was controlled at pH 7.0, hydrogen production was 2614.5 m1/1 in 17 hours. The increase of glucose concentration resulted in higher $H_2$ production. The productivity of this strain was 6.87 mmol $H_2/l$ per hi on concentration of 25g glucose/l. Enterobacter sp. SNU-1453 could utilize various sugars. These results indicate that Enterobacter sp. SNU-1453 has a high potential as a fermentative $H_2$ producer.

• 한국약용작물학회지
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• 제10권4호
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• pp.243-248
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• 2002

The effects of basal media, carbon, nitrogen, phosphate and some major macro elements on growth and shikonin production in Lithospermum erythrorhizon hairy root culture were studied. Among examined media, growth of hairy root cultured in B5 liquid medium was rapid, whereas shikonin production was high in MS liquid medium. Under B5 basal medium, sucrose concentration for optimal growth and shikonin production was 9% and 4% respectively. The growth and shikonin production on pH changes in B5 medium resulted little effect in pH 5.8 to pH 8.8 ranges, whereas growth was decreased dramatically in both above 8.8 and under 5.8. Nitrogen source and concentration effected on the growth and shikonin production. The highest growth rate was in B5 medium (50 mM $KNO_3$ and 1 mM $NaH_2PO_4)$, whereas the highest shikonin production was in the condition supplemented with 5 mM $KNO_3$ and 10 mM $NaH_2PO_4$.

• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.106-109
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• 2006

Improvement of L-asparate ${\beta}-decarboxylase$ production from Pseudomonas dacunhae ATCC 21192 was attempted by optimizing fermentation conditions. Optimum carbon and nitrogen sources for cell growth and enzyme production were determined. L-Glutamate (2%) was the most suitable carbon source, and D-glucose, D-glycerol and fumarate repressed enzyme production. Yeast extract (2%) was the most effective as nitrogen source. A slight change of pH to 6.5 from medium pH resulted in a meaningful increase in the production of enzyme. The production of the enzyme was highly improved by using 2% yeast extract and 2% L-glutamate in culture media. Maximum L-asparate ${\beta}-decarboxylase$ activity reached up to over 24 U/mL-broth by 15 h flask fermentation.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.351-355
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• 2003

Screening 실험을 통하여 결정된 주요인자인 sucrose, nitrogen, 배양온도로 인자의 최적수준을 결정하는 표면반응법중 하나인 Box-Behnken design을 수행하였다. 각 인자의 상관관계를 통하여 sucrose는 90 g/L, nitrogen은 41 mM, 온도는 $22^{\circ}C$가 최적수준으로 결정이 되었으며 확인실험을 통하여 대조구보다 세포생장이 증가하였을 뿐만 아니라 hGM-CSF의 생산도 약 2배 정도 증가되었음을 확인하였다. 이것은 고농도의 sucrose로 인해 배지내로의 hGM-CSF의 분비가 촉진되었기 때문이며 또한 저온으로 인해 분비된 hGM-CSF를 분해하는 protease 활성이 감소되었기 때문인 것으로 사료된다.

• 미생물학회지
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• 제46권1호
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• pp.46-51
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• 2010

Coenzyme Q10 (CoQ10)은 전자전달계에 필수적인 요소로 질병치료 및 완화에 도움이 되어 산업 의학적으로 그 활용도가 넓어지고 있다. 본 연구에서는 새로운 CoQ10 생산균주를 선별하기 위하여 quinone 분석 결과 CoQ10을 함유하는 것으로 확인된 8종 미생물의 생장특성과 CoQ10 생산능을 1차 조사하여, 세균류인 Paracoccus denitrificans KCTC 2530과 Asaia siamensis KCTC 12914를 대량배양을 통한 CoQ10 생산에 유리한 특성을 갖는 균주로 선별하였다. 이들 세균류의 생장 및 CoQ10 생산의 최적조건을 플라스크배양으로 조사한 결과, M81 배지를 기반으로 하여 탄소원으로는 4% fructose, 질소원으로는 2% yeast extract가 가장 좋은 것으로 조사되었으며, 배양온도는 $30^{\circ}C$, 배지의 최적 pH는 P. denitrificans KCTC 2530의 경우 pH 6.0, A. siamensis KCTC 12914의 경우 pH 8.0으로 조사되었다. 이를 바탕으로 2 L fed-batch culture를 수행한 결과, P. denitrificans KCTC 2530은 1 L 당 $14.34{\pm}0.473$ mg, A. siamensis KCTC 12914는 $12.53{\pm}0.231$ mg의 CoQ10을 생산하였다.

• KSBB Journal
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• 제30권2호
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• pp.82-90
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• 2015

Plant cell immobilization can protect plant cells from shear forces and increase the stability of gene. An additional advantage of immobilization is the easiness for performing continuous culture with cell recycling. Therefore plant cell immobilization can overcome the limitations of plant cell applications. In addition, target protein should be selected from pharmaceutical proteins to get rid of low expression level problem. The enhanced production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was investigated in immobilized Nicotiana tabacum suspension cell cultures. When the cells were immobilized in polyurethane foam, specific production of hGM-CSF was higher than that in alginate bead immobilization. Optimum continuous culture condition was the addition of 60 g/L sucrose in growth media with exchanging media every 6 day. Under the same condition, specific hGM-CSF production was 7 times higher in a 500-mL spinner flask than that in 100-mL Erlenmeyer flasks. Therefore, development of an effective immobilization process would be possible when the advantage of easy cell recycling was used. Consequently, enhanced production of target proteins could be possible in immobilized continuous cultures when the advantages of immobilization were applied.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.46-51
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions. Among lipases functioning under extreme conditions, alkaline lipase is useful in detergent industry. Lipase from yeast strain Yarrowia lipolytica NRRL Y-2178 was most active under alkaline condition, and initial medium pH for most lipase production was also alkaline [Lee et al., 2007, J Microbiol Biotechnol, 17(6)]. High lipase production was achieved using Y. lipolytica NRRL Y-2178. Optimal incubation time for lipase production at $25^{\circ}C$ was 72 h. Optimal temperature, when incubated for 72 h, was $27.5^{\circ}C$. Lipase production but not cell growth was very sensitive to concentrations of glucose and glycerol as efficient carbon sources, showing optimal concentrations of 1.0 and 1.5% (w/v), respectively. Lipase production was highly stimulated by $Ca^{2+},\;K^+,\;and\;Na^+$, but was inhibited by $Co^{2+},\;Cu^{2+},\;Mn^{2+},\;Na^+,\;and\;Fe^{2+}$. Maximum lipase production at 0.1 mM $Ca^{2+}$ for 72 h incubation at $27.5^{\circ}C$ was 649 units/mL.