• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.71-75
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• 1997

For the establishment of early selection of heat-tolerant clones through in vitro tuberization of true potato seeds, different temperature treatments for in vitro tuberization were investigated. The ratios of tuberization at 2$0^{\circ}C$ on var. Superior and DTO-33 treated with 5 mg/L of BAP and 500 mg/L of CCC, were 85% and 92%, respectively. At 3$0^{\circ}C$, the ratio of tuberization on DTO-33 was 37%, which revealed strongly heat-tolerant clone. In culture system of in vitro tuberization, the number of tubers per flask at 2$0^{\circ}C$ on non-subculture incubation was more than that on subculture incubation. The condition of non-subculture and short-day treatment for 4 weeks was good for production as 10.6 tubers per flask, which was very similar to that of long-day treatment. On the other hand, tuber diameter on long-day treatment was greater as 11.2 mm than on short-day treatment. Therefore, in vitro tuberization from true potato seeds could be induced under the condition of long-day treatment at darkness.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.481-490
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• 2001

The purpose of this study was to find out the problems on the fractional distillation experiments in the middle school science textbooks based on the 6th curriculum and to suggest an efficient experiment method for the middle school students. The first step was the classification of the experiments in 8 science textbooks according to heating apparatus and liquid mixtures. The second step was doing each experiment 3 times followed by the experimental process in the textbooks. The third step was developing the alternative experiments for solving the problems found in the second step. The heating method used in the alternative experiments were direct heating, oil bath, and heating mantle. The results of the second step showed that the direct heating experiment of branched round flask was more close to the theoretical prediction than the experiment of water bath heating of branched test tube. Also the direct heating experiment of thermally insulated branched round flask was better than the result of the experiment which was not insulated. The results of the third step showed that the experiment using heating mantle regulated heating power by observing the temperature of distillate gave the closest result to the theoretical prediction. From the above results, it is concluded that the experiment using branched test-tube with water bath heating is not adequate for the fractional distillation and an alternative experiment using insulated branched round flask with heating mantle regulated heating power during experiment is recommended.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.419-420
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• 2003

산업화가 진행되면서 야기된 지구온난화와 프레온 가스등의 증가로 인한 오존층 파괴 그리고 화석연료의 사용으로 인한 산성비 발생 등은 지구 환경문제로서 전 세계적인 관심이 되고 있다. 특히, 산업혁명 이후부터 꾸준히 증가하고 있는 온실가스는 기후변화에 있어서 양의 복사강제력(radiative forcing)으로 작용하고 있으며, 지표면의 온도를 높임으로서 기후의 다른 변화를 일으키는 매개체로도 작용하고 있다. 대기중에 온실가스 농도가 증가하게 되면 지구가 에너지를 우주로 방출하게 되면서 냉각되는 효과를 감소시키게 된다. (중략)

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.254-255
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• 2000

형질전환된 인삼 모상근의 여러 생물반응기에서의 대량배양 가능성을 알아보기 위하여 1/2 MS 배지를 기본배지(호르몬 무첨가, 3% sucrose)로 하여 실험을 수행하였다. 그 결과 플라스크 배양에 비하여 $2{\sim}3.5$배 높은 성장률을 보였으며, 그 성장이 왕성함을 알 수 있었다. 배양 후반기에 모상근의 뭉치 형성으로 물질전달의 어려움으로 인하여 성장에 장해를 미치는 것으로 사려된다.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.83-86
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• 1997

To produce and supply the healthy potato, basic seed potatoes were produced by stem cutting, microtuberization and hydroponic culture. The total number of tubers and the total tuber weight per $\textrm{m}^2$ of potato were more in hydroponic culture as each products were 1, 152 and 4, 492g than in the stem cutting (75 and 4, 136g) or microtuberization (1, 080 and 1, 080g) using petridishes. The total yield per 10a in the field was propagated highly stem cutting > propagated microtubers > hydroponics > microtubers. The number of tubers per 10a produced by hydroponics (33, 064) was higher than any other methods. This indicated the hydroponic culture can be used in the multiplication of basic seed potatoes.

• Korean Journal of Plant Tissue Culture
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• v.21 no.6
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• pp.341-345
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• 1994

The effect of phytohormones on in vitro production of ubiquinone 10 from the callus cultures of Nicotiana tabacum cv Xanthi was investigated. The growth of callus cultures of Xanthi was in proved by addition of NAA and 2,4-D, especially NAA 0.5 mg/L alone, at the light condition. Ubiquinone 10 was detected by HPLC, and confirmed from Xanthi callus cultured on the all of uppermedia. The ubiquinone 10 content in Xanthi tobacco callus cultured on the medium with NAA 0.5 mg/L only was higher than that of other mixed medium with NAA and 2,4-D. However addition of IBA 1 mg/L and NAA 0.5 mg/L to the medium was more effective in promoting ubiquinone 10 formation than that of NAA 0.5 mg/L only As the callus growth of Xanthi was considerabley restrained at concentration of kinetin, Content and production of ubiquinone low as the highest at kinetin 0.5mg/L and 2,4-D 0.5mg/L in the light.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.34-39
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• 1998

We have already prepared a human lysozyme (HLY) structural gene from chemically synthesized 38 oligomers with high codon usage in Saccharomyces cerevisiae. For directing the synthesis and secretion of HLY in S. cerevisiae, two types of expression vectors, a YCp centromere-based vector, pHK101 and a YEp 2-$\mu\textrm{m}$ circle-based vector, pHK501 were constructed. With the resulting plasmids, we have confirmed that yeast transformant harboring pHK501 has more secreted HLY than pHK101-transformant by using a lysoplate and a turbidimetric assay. In flask cultivation, pHK501-transformant produced active HLY about 8 times (55 units/$m\ell$) higher than pHK101-transformant. From batch cultivation, the HLY productivity was obtained with 1.12 units/$m\ell$/h, corresponding to a 1.8-fold increase compared with flask fermentation. These results indicate that yeast transformant with pHK501 vector overexpressed and secreted HLY than that of YCp type vector.

• Journal of Life Science
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• v.13 no.2
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• pp.214-222
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• 2003

The microorganism isolated from soil was identified as Bacillus coagulans by morphological and biochemical analyses and API-50CH/B kit, which was an identification kit for Bacillus species, and named as B. coagulans DL-1. It produced an extracellular biopolymer. Maximum production of biopolymer was 5.00 $\pm$0.15 g/$\ell$ in a $7\ell$bioreactor with an aeration rate of 1.0 vvm and an agitation speed of 500 rpm when concentrations of glucose and yeast as the optimal carbon and nitrogen sources were 2.0% (w/v) and 0.25% (w/v), which were optimized with a flask scale. Gas chromatographic analysis showed that the biopolymer producded by B. coagulans DL-1 consisted of glucose and rhanmose and their molar ratios was about 9 : 1. Its average molecular weight was 2.80$\times$$10^5$ with gel permeation chromatographic (GPC) analysis.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.34-39
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• 2005

In order to product the furofuranoid lignans, (+)-eudesmin which is one of the secondary products from Magnolia sieboldii. through cell suspension cultures; various culture media, initial sucrose concentration, elicitations, shaking speeds, and inoculum sizes. Among the culture media tested, MS medium had a pronounced effect on suspension cell growth and (+)-eudesmin contents. The maximum dry cell weight (DCW) of 3.71 g per flask was obtained at inoculum size of 0.5 g and in MS medium supplemented with $3\%$ sucrose plus 0.5 mg/L 2,4-D after 8 weeks. (+)-Eudesmin biosynthesis was stimulated with high initial sucrose concentration ,and the maximum (+)-eudesmin production of $3.2{\mu}g/g$ DCW was achieved at 200mg/L chitosan and $5\%$ initial medium sucrose. The optimal shaking speeds for dry biomass accumulation and (+)-eudesmin contents was 130 rpm. This work is considered to be helpful for large-scale bioprocessing of Magnolia sieboldii suspension cell cultures in bioreactor.

• KSBB Journal
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• v.13 no.5
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• pp.491-496
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• 1998

The production of fibrinolytic enzyme from Bacillus subtilis BK-17 was studied in the shake flask cultures. The important medium components studied include nitrogen source, carbon source and inorganic salts. The environmental conditions include initial pH, temperature, shaking speed and working volume. Among various N-sources, C-sources and inorganic salts tested, soybean flour, D-glucose and Na2HPO4 gave the best results, and their optimal concentrations were 1.5%, 0.5% and 0.05%, respectively. The optimal pH and temperature were 9.0 and 37$^{\circ}C$. With decreasing working volume in the range of 25∼100ml in the 250ml flask or increasing shaking speed in the range of 100∼300rpm, the enzyme production was greatly enhanced. The enzyme activity under the optimal conditions was about 1400I.U./ml with urokinase as a standard.