• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.541-546
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• 1990

Bacillus sphaericus ts-Dl290 was characterized by SDS-PAGE produced by the mutant at $30^{\circ}C$ and $42^{\circ}C$. The total amount of proteins produced by the mutant at $42^{\circ}C$ decreased to one-fifth of those at $30^{\circ}C$; however, when the culture was shifted down from $42^{\circ}C$ after 4 to $30^{\circ}C$, the total amount of protein decreased to one-third and the 221 kd protein did not appear, but the 155 kd appeared remarkably. When the mutant and the wild type strain were cultured in the media containing 80$\mu g$ per ml of chloramphenicol at $42^{\circ}C$, the wild type strain synthesized half amounts of the total proteins than those at $30^{\circ}C$, and the mutant produced one-tenth of the total protein amounts. When the both strains were cultured in the media containing chloramphenicol, the 155 kd protein was produced was produced in lesser amounts than those without chloramphenicol. The 150 kd protein showed lethal activity to Culex pipiens 3rd instar larvae.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.228-232
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• 2005

A yeast strain producing phytase, isolated from a mash of Korean traditional Yakju, was identified as a strain of Saccharomyces cerevisiae and designated as Saccharomyces cerevisiae CY strain. Phytase was produced by CY strain both intracellularly and extracellularly. Total phytase activity by the shaking culture was about two times higher than that of the static culture. The portion of extracellular phytase to total phytase activity ranged between 23 and 49 percent, depending on the glucose concentration in the culture medium. Phytase production was reached at approximately 1 U/ml as total phytase activity and the maximum intracellular phytase activity was 0.17-0.19 U/mg-DCW at late logarithmic growth phase. The optimum reaction pH and temperature of intracellular phytase were 3.5 and $40^{\circ}C$, respectively. Over 95% of the phytate was degraded by growing cells after 36 hours yeast cell culture and about 90% of total phytate was effectively degraded by suspending the whole cell with the biomass of 0.4 mg-DCW/ml-reaction solution after 12 hours degradation reaction.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.3
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• pp.209-212
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• 2002

We obtained regenerated Italian ryegrass (Lolium multiflorum Lam.) plants by anther culture. When Italian ryegrass anther was incubated for 20 days on callus induction medium, MS medium containing 30 g/$\ell$ of sucrose, 2 mg/$\ell$ of NAA and 1 mg/$\ell$ of kinetin, its callus was induced. The ratio of callus induction was 9.2 %, the mean of callus weight was 8.6 mg/callus/anther. When Italian ryegrass callus was incubated for 50 days on plant regeneration medium, MS medium containing 30 g/$\ell$ of sucrose, 1 mg/$\ell$of NAA and 2 mg/$\ell$of kinetin, Italian ryegrass plant was regenerated. The ratio of plant regeneration was 26%.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.71-76
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• 1999

Anthers of two hot pepper cultivars, Milyang-jare and Geryongsan-jare, were cultured on MS medium containing 0.1 mg/L 2,4-D and 0.1 mg/L kinetin. The influence of pretreatment at 4$^{\circ}C$ and 32$^{\circ}C$ on induction of microspore embryo was investigated. Milyang-jare was superior to the Geryongsan-jare in microspore embryo induction. The 32$^{\circ}C$ pretreatment increased embryo induction compared to the 4$^{\circ}C$ pretreatment while the 4$^{\circ}C$ pretreatment stimulated callus induction. Microspore embryos were regenerated to plantlets in the same medium or hormone free medium at 32$^{\circ}C$ treatment but most embryos failed to develop directly into plantlets at 4$^{\circ}C$ treatment. The optimal period of the 32$^{\circ}C$ pretreatment was 3 days in Milyang-jare and 6 days in Geryongsan-jare. The 32$^{\circ}C$ pretreatment was essential for induction and growth of microspore embryo in pepper.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.271-275
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• 2005

본 연구는 치주낭에 biofilm형태로 부착되어 질환을 유발시키고 항생제 빚 항균제에 저항을 일으키는 세균 독성요소를 규명하기 위해 시행된 기초연구이다. 치주질환의 주 병원균의 하나인 Porphyromonas gingivalis 381 biofilm의 세포외막에 특이하게 발현되는 단백질을 규명하기 위한 기초적인 자료를 얻기 위해 시행하였다. Porphyromonas gingivalis 381을 통상적인 세균 배양용 broth를 사용하여 혐기성 세균 배양기로 24시간 배양한 것을 대조군으로 하고, tissue culture plate를 이용하여 혐기성 배양조건 하에서24시간동안 biofilm을 형성하여 실험군으로 설정하였다. 세균을 수획하여 세포외막을 분리하고 isotonic isoelectric focusing을 시행한 결과 주로 약 20-30 kilodaltons에 해당하는 수종의 세균세포막 단백질이biofilm으로 배양한 세균에서 더 상승적으로 발현됨이 관찰되었고, 상이한 수종의 단백질도 planktonic culture broth로 배양한 세균에서 다 상승적으로 발현됨을 관찰할 수 있었다. 이것은 세균의 배양조건과 환경에 따라 그 외막 단백질이 서로 다르게 발현됨을 입증하는 기초적인 자료로서 향후 단백질의 동정과 성격을 규명하는 근간 실험으로 추진할 계획이다.

• Journal of Embryo Transfer
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• v.14 no.2
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• pp.89-92
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• 1999

효율적인 homozygous 동물을 생산하기 위한 실험의 단계로 염색체가 4배체인 수정란의 이용성을 타진하기 위해 생쥐 수정란과 cytochalasin B를 사용하여 4배체 유도에 관한실험을 수행하였다. 생쥐 2-세포기 수정란을 10$\mu\textrm{g}$/ml 농도의 cytochasin B로 약 20시간 배양하였을 때 모든 수정란은 발육을 거의 멈추었으나, 이 수정란을 cytochalasin B-free medium에 체외배양하였을 때 발육이 재개되어 48시간 후 상실기나 배반포기까지 약 74%의 발육율을 나타내었다. 그러나 발육된 수정란의 세포수는 대조구에 비해 휠신 적은 것으로 나타났다. 염색체 분석결과 cytochalasin B로 처리한 대부분의 수정란은 4배체인 것으로 나타났고 약간의 수정란은 mosaicism과 다배체를 나타내기도 하였다. 그러므로 cytochalasin B를 이용하여 효과적으로 4배체의 수정란을 유도할 수 있는 것으로 나타났다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.41-44
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• 1977

Production of haploids in vitro anther culture of Nicotiana tabacum L. was oriented in a large number on a chemically defined culture medium. The haploids were screened for T.M.V. resistance and the segregating ratio in F$_1$ were in good agreement with the expected ratio.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.165-168
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• 1995

The embryos formed from anther culture of peony exhibited divergent morphologies. The frequency of normal embryos with two cotyledons was about two times higher in the embryos formed through direct embryogenesis than those formed from callus. About 69% of the embryos with two cotyledons converted into normal plants, but convention rate of the abnormal embryos with one and three or four cotyledons was only 4 to 9%. The embryos of hem and bowling pin shape did not undergo development into normal plants.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.319-322
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• 1998

Culture conditions for high frequency embryogenesis and plant regeneration in anther cultures of various F$_1$ hybrid and homozygous lines of pepper (Capsicum annuum L.) are described. Anthers pigmented less than halfway from the distal end were dissected from the flower bud in which petals elongated 2 mm higher than the receptacle. They were placed on Dumas medium supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin. After four weeks of culture, embryos began to appear on anthers. After eight weeks of culture, frequencies of embryo formation reached up to 58.3%. Upon transfer to MS basal medium, greater than 95% of embryos developed into plantlets.

• KSBB Journal
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• v.5 no.1
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• pp.43-47
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• 1990

It was determined optimal Culture conditions and suitable growth regulators for seed germination, growth of callus, and protoplasts derived from cultured and mesophyll cells in Gremastra appendiculata. Induction of fusion between protoplasts of cultured and mesophyll cells was examined. The best conditions of seed germination and growth of callus were achieved on Hyponex medium contained plant growth regulators(2mg/l 2, 4-D, lmg/l Kinetin). Viability and regeneration of cell wall in protoplasts was determined with fluorescence microscope. Also, fused protoplasts were achieved by using PEG solution between protoplasts of cultured and mesophyll cells.