• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.465-468
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• 2002

부패한 사과로부터 bacterial cellulose (BC)를 생산할 수 있는 균주를 분리한 후 배양조건에 따른 BC의 생산량을 조사한 결과 BC의 생산량은 진탕배양한 경우가 정치배양한 경우보다 약 1.5배 높았다. BC의 생산량을 높이고자 mutagen으로 UV와 cylcloheximide를 사용함으로써 BC 생산량을 약 3배 증가시킬 수 있었다.. 미생물에 의해 생성된 BC는 종이나 펄프와는 달리 pectin, 납, 유지, 단백질, 무기질 등의 불순물을 함유하지 않는 filter paper와 성질이 유사한 것으로 나타났다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.48-49
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• 1998

생쥐 수정난 및 초기 2세포배를 체외배양시 0.428mM 이상의 칼슘 농도를 필요로 하는 것을 알았다. 칼슘 chelator인 EDTA를 저농도로 배양액에 처리 할 경우 2-cell block이 유의하게 극복되었으며, 저농도의 칼슘이 존재하는 배양액에서 보인 2-cell block은 니켈 50 $\mu$ M을 처리함으로서 극복 효과를 보였다. EDTA와 니켈에 의한 2-cell block 극복 현상이 어떠한 기작에 의해 이루어지는가에 대한 자세한 연구가 필요하다고 생각된다.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.115-123
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• 2003

The present study was carried out to examine the effect of catalase (CAT) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with CAT on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows - 1 . The rates of nuclear maturation, penetrated oocytes, pronucleus formation rates, polyspermic oocytes and mean numbers of the penetrated sperm were significantly lower in oocytes matured with 100, 500 and 1,000 units/ml CAT than those of central groups (P>0.05). 2. The rates of blastocyst formation and total cell numbers of blastocyst at day 7 after in vitro fertilization were significantly lower in CAT treatment groups than those of the central groups (P>0.05). 3. There were not significant difference in the blastocyst development and total cell numbers of blastocyst on in vitro culture of NCSU-23 media with 0, 100, 500 and 1000 units/ml CAT under the 5% and 20% $O_2$ concentrations. These results suggested that the addition of CAT was not helpful for porcine oocyte maturation and further development, also the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under the 5% and 20% $O_2$ concentrations.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.2
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• pp.95-103
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• 2001

연구목적: 본 연구는 생쥐 preantral follicles의 체외 배양 조건을 확립하고 이를 기초로 높은 체외 발달률 그리고 산자 생산률을 얻고자 하였다. 연구재료 및 방법 : Preantral follicles의 oocyte-granulosa cell complexes (OGCs)는 생후 12일된 FI ($C57BL{\times}CBA$)으로부터 난소를 적출하여 효소를 이용한 방법을 통해 획득하였다. 회수된 complexes는 10일 또는 12일 동안 체외 성장을 위해 Transwell-COL membrane insert로 옮겨졌고 5% FBS, 100 mIU/ml FSH, 100 mIU/ml hMC가 첨가된 ${\alpha}MEM$에서 배양되었다. 체외 성숙을 위해 1.5 IU/ml hCG가 첨가된 ${\alpha}MEM$에서 18 hrs 배양을 실시하였다. 그 후 M16에서 수정능력이 획득된 정자와 수정을 하여 4 hrs, 7 hts, 9 hrs 후에 10% FBS가 첨가된 modified M16 배양액에서 4일간 배양하거나 또는 bovine cumulus cell과 co-culture를 실시하였다. 그리고 형태적으로 정상적인 22개의 상실배와 포배를 2마리의 위임신 대리모 (ICR)의 자궁에 이식하여 산자 생산을 유도하였다. 결과: 1) OGCs 크기가 mouse preantral follicles의 핵 및 세포질 성숙에 미치는 영향을 조사하였을 때 $120{\sim}150{\mu}m$의 preantral follicles (MII: 33.0%, 난할률: 36.7%, 상실배 이상; 20.9%)은 핵 및 세포질 성숙에 있어서 $70{\sim}110{\mu}m$ (MII: 12.2%, 난할률: 10.2%, 상실배 이상: 4.8%)보다 더 높았다(p<0.001). 2)체외 성장기간의 연장이 mouse preantral follicles의 핵 및 세포질 성숙에 미치는 영향을 조사하였을 때 10일 (난할률: 38.2%)은 12일 (난할률: 20.0%)보다 난할률에서만 더 높았다 (p<0.01). 3) 체외 수정 시간의 연장이 mouse preantral follicle의 세포질 성숙에 미치는 영향을 조사하였을 때 9 hrs (난할룰 31.5%, 상실배 이상: 14.3%)은 4 hrs (난할률: 17.5%, 상실배 이상: 4.8%), 7 hrs (난할률: 20.4%, 상실배 이상: 6.1%) 보다 세포질성숙에 있어서 유의하게 높은 발달률을 나타냈다 (p<0.01). 4) 공배양이 mouse preantral follicle의 세포질성숙에 미치는 영향을 조사하였을 때 공배양 (상실배 이상: 17.4%)을 실시했을 때와 M16 (상실배 이상17.4%)에서 배양되었을 때는 차이가 없었다. 5)preantral follicle의 크기 ($120{\sim}150{\mu}m$), 체외 성장기간 (10일), 체외 수정 기간 (9시간), 배양 환경 (단지 medium만 존재)의 적절한 결과들을 종합하여 수행하였을 때 MII 성숙률, 난할률, 상실배 이상의 발달률은 30.2%, 39.3%, 22.5%이었고 총 22개의 상실배 및 포배를 2마리의 대리모에 이식했을 때 1마리가 임신했고 1마리의 산자를 생산했다. 결론: 따라서, 본 실험은 preantral follicle을 이용한 체외 배양 시스템이 생쥐 oocyte를 공급하는 또 다른 방법으로 효과적으로 이용될 수 있다는 것을 시사한다.

• Journal of Embryo Transfer
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• v.20 no.2
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• pp.137-145
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• 2005

본 연구는 NCSU-23과 PZM-3 배양액에 EGF, $\beta-ME$와 glucose의 첨가가 돼지 난자의 체외성숙에 미치는 영향과, 배양조건을 다르게 하여 계대배양한 섬유아세포를 이용한 핵이식 배를 다른 배양액과 산소조건에서 배양하였을 때 체외발생율에 미치는 영향을 조사하였다. 난자를 20ng/ml EGF를 첨가 또는 첨가하지 않은 NCSU-23 및 PZM-3 배양액에서 44시간 배양하였을 때 난자의 체외성숙율은 각각 $85.7\pm3.1\%,\;75.2\pm2.8\%,\;87.1\pm2.4\%$와 $78.2\pm2.6\%$였으며 EGF를 첨가한 배양액에서 배양한 난자의 체외성숙율은 EGF를 첨가하지 않은 배양액에서 배양했을 때의 난자보다 높은 체외성숙율을 나타냈다(p<0.05). 난자를 $25{\mu}M\;\beta-ME$를 첨가 또는 첨가하지 않은 NCSU-23 및 PZM-3 배양액에서 44시간 배양하였을 때 난자의 체외성숙율은 각각 $79.5\pm2.6\%,\;74.7\pm2.5\%,\;80.2\pm2.3\%,\;78.6\pm2.7\%$였고 $\beta-ME$를 첨 가한 PZM-3 배양액에서 배양한 난자의 체외성숙율이 가장 높게 나타났다. 난자를 1.5mM glucose를 첨가 또는 첨가하지 않은 NCSU-23 및 PZM-3 배양액에서 44시간 배양하였을 때 난자의 체외성숙율은 각각 $79.2\pm2.3\%,\;75.0\pm2.6\%,\;85.5\pm2.5\%$와 $78.9\pm2.7\%$였고, glucose를 첨가한 PZM-3 배양액에서 배양한 난자의 체외성숙율은 glucose를 첨가하지 않은 PZM-3 배양액에서 배양한 난자보다 높은 체외성숙율을 나타냈다(p<0.05). 핵이식 배를 20ng/m1 EGF, $25{\mu}M\;\beta-ME$ 및 1.5mM glucose를 첨가한 NCSU-23 및 PZM-3 배양액에서 48시간, 144시간 배양하였을 때 2세포기 및 배반포로의 체외발생율은 각각 $56.4\pm2.7\%,\;54.3\pm2.9\%,\;70.5\pm2.1\%,\; 69.6\pm1.5\%$ 및 $12.0\pm1.3\%,\;9.6\pml.7\%,\;10.9\pm2.1\%,\;11.9\pm1.8\%$였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.365-376
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• 2020

Immature embryogenesis is a useful process in wheat tissue culture, including transgenic technology, because of its high regeneration efficiency compared to that in other tissues. However, it is a very labor-intensive and time-restrictive method, because the preparation of immature embryos is limited to the optimal time after flowering. In this experiment, 'Speed Breeding', a breeding technique that accelerates breeding generation advancement by extending the photoperiod, was applied to the wheat variety 'Bobwhite'. A controlled growth room was constructed by adjusting the photoperiod (22-hour light/2-hour dark) using LED lights at temperature of 22℃. After vernalization of the Bobwhite seeds at 4℃ for 4 weeks, the seedlings were grown in a controlled growth room and a greenhouse to compare the heading date. In both conditions, calli were induced from immature embryos on the 11^th day after flowering. After 4 weeks, the calli were transferred to a regeneration medium. Regeneration efficiencies under greenhouse conditions and Speed Breeding conditions were determined as 45.05% and 43.18%, respectively. Antioxidant enzyme activity and reference gene expression analysis were performed to confirm the presence of stress due to an extremely long-day photoperiod. As a result, the antioxidant enzyme activity was not distinguished from that of the greenhouse condition. The reference gene expression analysis revealed that the PsaA and CDC genes were highly expressed under the Speed Breeding condition. However, expression of PsbA was similar expression in both conditions. These results will provide useful information for the application of immature embryogenesis to the wheat transformation system.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.301-304
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• 2002

Perfusion culture strategies for high density culture of plant cell suspensions to enhance the productivity of extracellular polysaccharides were investigated. Angelica gigas Nakai cell suspensions were used to produce the extracellular polysaccharide and perfusion parameters were optimized to maximize the production. When the medium exchange was started at the fifth day after inoculation, the maximum cell concentration (23.8 g dry cell weight per liter) was achieved.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.51-55
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• 2010

A lactic acid bacterial strain showing fast growth and high acid production in Korean pear puree was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc (Ln.) mesenteroides KACC 91495P. Korean pear puree was fermented using Ln. mesenteroides KACC 91495P strain at $30^{\circ}C$ for 18 h. The changes of pH, titratable acidity and viable cell number during fermentation were investigated. The pH and titratable acidity were reached to pH 3.86 and 1.09% after 18 h fermentation, respectively. The viable cell population of Ln. mesenteroides KACC 91495P was rapidly increased to $2.0{\times}10^9\;CFU/g$ during the 9 h of cultivation. The contents of lactic acid, acetic acid and malic acid were determined to be 0.213, 0.259, and 0.217% after 18 h fermentation, respectively. The content of polyphenolic compounds, known as antioxidants, in pear puree were enhanced by Ln. mesenteroides KACC 91495P cultivation. The level of total polyphenolic compounds was increased to around 140% of initial concentration. When the fermented pear puree was kept at $4^{\circ}C$, pH, titratable acidity and number of viable cells population were nearly maintained for 13 days.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.39-44
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• 2005

An effective micropropagation system for Liriodendron tulipifera L via somatic embryogenesis was established using immature seeds. Immature seeds from five individual trees were bisected longitudinally and cultured on two basal media (MS and B5) containing different combinations of 2,4-D and TDZ to induce callus and embryogenic tissue under light ($40{\mu}mol\;m^{-2}s^{-1}$, 16 hr/day) or complete darkness at $25{\pm}2^{\circ}C$. There was no distinctive difference on callus and embryogenic tissue induction between the two basal media with PGRs. Optimum culture medium appeared to be MS medium supplemented with 1.0mg/L 2,4-D and 0.01mg/L TDZ plus 3% sucrose. Nonembryogenic callus induction rate was not significantly different among the genotypes. However, However, the embryogenic callus induction frequency differed greatly by the genotypes ranging from 55% to 72% when cultured in the dark. Generally, the cultures maintained in the dark tended to show normal somatic embryo development as well as embryogenic tissue formation and this was confirmed by histological examination. Above results suggest that a proper selection of mother tree and dark culture condition are necessary to optimize somatic embryogenesis system of Liriodendron tulipifera.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.363-373
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• 2007

To establish an efficient and reliable microspore culture system for pepper (Capsicum annuum L.), the effect of light intensity used for donor plant's growth, microspore isolation methods, the composition of culture medium, and culture period in light on the production of embryos were investigated. The viability of microspores taken from the plants grown under the light intensity of 10,000 lux was almost same as that from the lower (5,500 lux) light intensity, and the embryo induction and development were a bit higher when donor plants were grown under the lower light intensity. This result implies that lower light intensity does not interfere with the embryo induction and development. However, it was very difficult to prepare microspores for culture since only a small number of flower buds could be harvested from plants grown under the light intensity of 5,500 lux. Microspore isolation methods greatly affected microspores viability; that is, when microspores were isolated by blending rather than maceration, the greater number of viable microspores were easily generated (about 13 times). Among media used for microspores culture in this study, MN medium was most efficient for embryo induction and development. Total number of embryos and the number of cotyledonary embryos were highest when microspores were cultured in dark for 4 weeks, and then in light for one week. These results will be provide valuable information to set up efficient microspore culture system of hot pepper with a high frequency of embryo production, which are applicable to gene transformation and mutagenesis.