• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.106-106
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• 2005

• Bioindustry News
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• v.14 no.4
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• pp.35-40
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• 2001

• Bioindustry News
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• v.14 no.3
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• pp.23-32
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• 2001

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.267-275
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• 2005

차세대 재생산성 에너지로 각광을 받고 있는 바이오디젤은 현재 주로 알칼리촉매를 이용하는 화학공정으로 생산하고 있으나 고에너지 요구성이며 대규모 생산시 폐수발생 등 환경오염 유발요인이 있기 때문에 친환경 생물공정의 필요성이 대두되고 있다. 생물촉매 리파제(lipase)를 이용하는 친환경 생물공정은 화학공정에 비해 다양한 장점을 제공하고 있으나 고가의 효소생산 비용문제로 실용화에 어려움이 있다. 따라서 본 연구에서는 저비용의 생물학적 바이오디젤 생산 시스템 구축을 위해 고활성의 효소 개발, 경제적 재조합 대량생산, 반복 재사용을 위한 효소고정화 등을 통해 고효율의 생산반응계를 개발하였다. 우선 바이오디젤 생산공정에 적합한 리파제로서 CalB(Lipase B of Candida antarctica)를 선택하고 분자 진화기술을 이용하여 효소활성을 17배 향상시킨 CalB14를 개발하였다. CalB14를 효모 발현시스템을 이용하여 경제적 대량생산하기 위해 단백질분비를 획기적으로 개선할 수 있는 맞춤형 분비융합합인자기술(TFP technology)을 이용하여 재조합 CalB를 2 grams/liter 수준으로 분비생산하였다. 생산된 효소를 반복 재사용이 가능하도록 다양한 레진에 고정화하였고 최적의 바이오디젤 전환반응용 고정화효소를 개발하였다. 고정화효소를 효율적으로 재사용하기 위해 바이오디젤 생산용 고정상반응기(packed-bed reactor)를 제작하였으며 기질을 12시간내에 95% 이상 바이오디젤로 수십회 이상 반복전환할 수 있는 경제적인 생물학적 바이오디젤 전환 시스템을 구축하였다.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.217-223
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• 2013

Pueraria lobata, a medicinally important leguminous plant produces various isoflavones including puerarin, daidzin and daidzein which are metabolized to equol via dihydrodaidzein and tetrahydrodaidzein by the bacterial fermentation of natural isoflavone sources in human intestines. In this study, we described callus proliferation and isoflavone production in callus of Korean wild arrowroot and dihydrodaidzein biosynthesis in callus extract fermented with Pediococcus pentosaceus. Proliferation was the best at callus cultured in the medium containing 1.0 mg/L TDZ and 1.0 mg/L NAA at light condition for 12 days. Puerarin was significantly more produced at callus cultured in the medium containing 2.0 mg/L kinetin and 1.0 mg/L NAA at dark condition for 16 days, but daidzin and daidzein were not significant. Callus extract was successfully fermented with P. pentosaceus and dihydrodaidzein, which is one of equol precursors formed by biotransformation, was confirmed to be produced. These results will facilitate mass production of callus and isoflavones as equol precursors from Korean wild arrowroot and can be applied for the production of equol by biotransformation in vitro.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1466-1475
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• 2021

Compound K (20-O-β-(_D-glucopyranosyl)-20(S)-protopanaxadiol) is an active ingredient of ginsenosides. Compound K has been known to produce from biotransformation by β-glucosidase action of human intestinal microbes after oral admistration of ginseng. We have investigated the cytotoxicity of compound K obtained from bio-converted ginseng extract. As a result, compound K showed no significant cytotoxicity in the concentration of 0.001 to 1 ㎍/mL and inhibited the production of TNF-α, MCP-1, IL-6 and NO in RAW 264.7 cells induced by LPS inflamation. In the same concentration, HaCaT cells induced by inflammation with TNF-α and IFN-γ decreased IL-8 production due to compound K treatment. In the brine shrimp lethality assay, the LC₅₀ of compound K was 0.37 mg/mL indicating some toxicity, but the bioconverted product containing 35% compound K showed relatively low toxicity with an LC₅₀ of 0.87 mg/mL. These results suggest that the compound K enriched extract is a potential functional material for acne relief cosmetic products.

• KSBB Journal
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• v.15 no.3
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• pp.268-273
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• 2000

A microbiological hydrogen production process was optimized. Anaerobic photosynthetic bacteria like Rhodospirillum rubrum which is known to produce hydrogen from carbon monoxide efficiently and remove sulfur was used. To evaluate the potenital of this microorganism the optimization of media fermentation condition light intensity and light requirement for CO conversionwas tried in batch cultures and the continuous fermenter was also applied for this process. The gas residence time on CO conversion was sought out to get high conversion of carbon monoxide to hydrogen. Through this study the possibility of microbial synthtics gas concersion process was proposed.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.185-194
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• 2006

Chloroplasts are believed to be descended from certain cyanobacteria, which were taken up by phagocytosis into a host cell and lived there in a symbiotic relationship. In contrast to the current static concept on the chloroplast genome, its dynamism has been recently demonstrated: the chloroplast genome is active in intramolecular homolgous recombination, producing subgenomic circles when it obtains homolgous sequences via genetic transformation. Chloroplast tranformation in higher plants provides many advantages over nuclear transformation that include higher expression levels of transgenes, polycistronic expression of transgenes, and maternal transmission of transgenes. Tobacco has been used as a model for chloroplast genetic transformation. However, it is recently possible to transform the chloroplasts of other major food and economic crops including rice, soybean, and cotton. Chloroplast-transformed crops will be able to replace bioreactors using microorganisms for production of value-added proteins in future.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.288-288
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• 2003

• Bioindustry News
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• v.11 no.1
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• pp.23-29
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• 1998