• Journal of Plant Biotechnology
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• 제6권3호
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• pp.193-197
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• 2004

In vitro multiplication of Curculigo orchioides was achieved by direct somatic embryogenesis in young leaf segments. Immature leaf segments of about 0.5 cm in length were cultured on MS medium supplemented with different concentrations of BAP (2-10 $\mu{M}$) or Kin (2-10 $\mu{M}$). Optimum response in terms of per cent cultures responding (89%) and the number of embryos per explant (16) were observed on MS medium supplemented with 8 $\mu$M BAP. The emergence of several somatic embryos on the adaxial side of the leaf segments was observed one month after the culture. Germinated somatic embryos were grown up to about 1.5 cm length before transferring to maturation medium. For maturation, the individual embryos were isolated and transferred to MS medium supplemented with BAP (5 $\mu{M}$) and NAA (0.5 $\mu{M}$). The plantlets emerged from the embryos were transferred to soil containing 1 peat: 1 sand with 90% success. The embryos were formed directly on the leaf segments without any callus phase. Direct regeneration of somatic embryos is important for the conservation of this endangered species, as rare somaclonal variants are likely to arise than from indirect regeneration.

• KSBB Journal
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• 제11권6호
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• pp.726-732
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• 1996

은행나무( Ginkgo bilaha 1.)의 잎으로부터 flavo­n noids 화합물틀을 Amberlite XAD-7으로 흡착시 키 는 최적 조건에 대한 연구를 수행하였다. 흡착제의 투입량, 수용액의 pH, 수용액의 조성 등의 흡착 조 건을 달리 하면서 flavonoids 화합물들의 흡착 경향 을 조사한 결과 20% 의 에탄올이 첨가된 pH 5.0의 수용액에 XAD-7이 15g/L의 양으로 투입된 경우 가장 선택적인 흡착이 이루어졌다. 이 경우 유기용 매 추출에 비해 약 98% 이상의 flavonoids 화합물 이 XAD-7에 흡착되었으며 selectivity도 약 50% 이상 증가된 85%를 나타내었다. 잎 내에 존재하는 여러 가지 화합물들 중 극성인 물질들은 수용액 내 에 용해되어 분리가 이루어졌고 flavonoids 화합물 에 비해 비극성인 지용성 물질들과 polyphen이류 등 은 흡착제가 투입되면 hydrophobic attraction에 의해 aggregation을 이루면서 석출이 되었다. 이로 인해 flavonoids 화합물들만이 흡착제로 이통하게 되 었다. 이와 같은 흡착 공청은 기존의 유기용매 추출 법에 비해 공정에 소요되는 경비와 시간을 크게 감 소시켜 새로운 분리 방법의 지표를 제시할 수 있을 것으로 기대된다.

• Animal cells and systems
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• 제2권2호
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• pp.239-242
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• 1998

Arabidopsis trp1 mutant plants, deficient in phosphoribosyI anthranilate transferase (PAT) activity, accumulate anthranilate compounds, which render them blue fluorescence. The visible phenotype of trp1 makes the PAT gene an excellent reporter gene in the mutant. In order to develop a system for the homologous recombination using the phenotypic characteristic of trp1-100, we established optimum conditions for the isolation and regenera tion of protoplast from auxin-conditioned, trp1-100 root cultures. Trvptophan had to be supplemented in the germination medium for the efficient cell division and subsequent plant regeneration. When 10 uM tryptophan was added to the germination medium, we obtained the highest yield of protoplasts ($3{\times}10^6 cells/g$) and the best viability (92%). Thirty percent of root protoplast derived from meristematic cells underwent cell division within 5 days in callus-induction medium. Regenerated rosette leaves (2-3 mm) were transferred to rooting medium and finally acclimated to the soil for flowering.

• 한국식품영양과학회지
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• 제31권3호
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• pp.389-393
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• 2002

청국장에서 분리한 Bacillus subtilis CH-1, Bacillus circul문 K-1과 Bacillus subtilis(natto) N-1 모두 biosurfactant를 생성하며 이 중 Bacillus subtilis CH-1가 가장 큰 생성력을 나타냈다. Biosurfactant를 대량 생산하기 위하여 AM, LM, NB과 TSB 배지중 AM을 기본배지로 선정하여 최적 탄소원과 질소원으로 glucose 2%, soy peptone 0.3%와 무기염을 포함하는 합성배지를 완성하였다. Biosurfactant의 생성은 96시간에 최대를 나타냈으며 이때 배지의 표면장력은 초기값의 약 43% 값을 나타냈다. 한편 배양온도 및 pH는 biosurfactant생산에 크게 영향을 주지 않았으며 pH5.0~8.0범위에서 대체적으로 안정한 생성을 유지하였다. 최적조건에서 배양시 crude biosurfactant 수율은 6 g/L를 얻을수 있다.

• Journal of Plant Biotechnology
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• 제5권2호
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• pp.131-135
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• 2003

Callus and cell suspension cultures of Eurycoma longifolia Jack were initiated from leaves of different trees. The leaf explant of tree Eu9 produced the most calli and also induced high cell biomass in the cell suspension culture. Optimum production of cell biomass could be initiated in proliferating culture medium with a pH of 5.75 prior to autoclaving. The effects of macronutrient inorganic salts of Murashige and Skoog (MS) liquid medium supplemented with X on production of cell biomass of Eurycoma longifolia were also investigated. The highest cell biomass was produced in MS medium containing macronutrients of $21\;mM\;NH_4NO_3,\;12.25\;mM\;KNO_3,\;3.00\;mM\;CaCl_2.2H_2O,\;0.575\;mM\;MgSO_4.7H_2O$, and $1.83\;mM\;KH_2PO_4$. A new medium labeled as TAM was formulated for the production of Eurycoma longifolia cell biomass in the cell suspension culture.

• 한국육종학회지
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• 제42권3호
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• pp.207-211
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• 2010

'Taedong Valley' is a high yielding and processing potato cultivar, which is a clonal selection resulting from a cross between 'W870' and 'A88431-1'. It is a medium maturating cultivar with medium plant height and light green foliage. 'Taedong Valley' has profuse flowering habit and light purple flowers. Tubers are smooth, round, and with yellow skin, light yellow flesh, medium eye depth. Tubers have medium dormancy and good keeping quality. 'Taedong Valley' has stable yield under wide range of climatic conditions. It is resistant to common scab and potato virus Y, but moderately susceptible to late blight. It is also resistant to most of the disorders, particularly dehiscence, hollow heart and internal brown spots. This cultivar has high level of tuber uniformity and capable of yielding 43.6 t/ha which is about 9.0% higher than the control potato cultivar 'Atlantic' under optimum agronomical practices.

• 한국식품저장유통학회지
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• 제6권2호
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• pp.221-227
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• 1999

고정화 배양계를 이용하여 감 즙으로부터 식초생산을 효율적으로 행하기 위하여 Saccharomyces cerevisiae의 고정화 형성조건을 검토하였다. 고정화를 위한 최적 Na-alginate의 농도는 2%이었다. 담체의 농도를 1-4%로 변화시키면서 gel beads로부터 누출되는 효모 균수를 검토한 결과, 1%의 농도에서는 배양 8시간째부터 배양액의 탁도가 흐려지는 것이 관찰되어 배양 20시간째에 0.82의 흡광도를 나타내었다. 그러나 2-4%에서는 거의 변화가 없었다. 배양이 끝난 후, 전자현미경으로 gel beads내부의 균주 생육상태를 관찰한 결과 고정화한 효모는 Na-alginate의 농도에 관계없이 왕성하게 생육하였다. Gel beads의 크기는 2-3mm정도가 최적이었고, 효모의 최적 접종량은 약 33mg이었다. 효율적인 에탄을 생산을 위한 산소공급 시간을 검토한 결과, 배양초기부터 12시간까지는 면전으로 호기적 배양을 행하고, 그 이후부터는 check valve가 부착된 실리콘 plug를 사용하여 혐기적 배양을 행하는 것이 효과적이었다.

• Journal of Plant Biotechnology
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• 제31권4호
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• pp.295-300
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• 2004

구기자나무의 잎 절편을 A. rhizogenes strain, 15834와 공동 배양하여 유도된 모상근의 최적배양조건을 결정하기 위하여 MS배지와 sucrose의 농도를 다양하게 처리한 결과, 1/2 MS 배지에서 생체중 (12.3 g)과 건물중 (1.4 g)으로 가장 높게 나타났으며, 탄소원으로 사용된 sucrose에서는 3% 농도에서 생체중과 건물중이 가장 양호하게 나타났다. 이와 같이 결정된 MS농도와 sucrose의 농도를 이용하여 대량배양을 하고자 10 L의 air lift bioreactor에서 대량 배양한 결과 역시 1/2 MS와 3% sucrose의 농도를 사용한 처리구에서 가장 높은 생체중과 건물중의 증가를 보였다. 하지만, 1/2 MS에 5% sucrose를 처리한 bioreactor배양에서도 3% sucrose처리에서와 마찬가지로 생체중과 건물중이 높게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.1-7
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• 2000

Bioconversion of fumarate to succinate was anaerobically conduced in a synthetic medium containing glycerol as a hydrogen donor and fumarate as a hydrogen acceptor. We investigated the effects of pH, carbon and nitrogen sources, conversion substrate, and other culture conditions on the production of succinate using a nwely isoloated Enterococcus facalis PKY1. Addition of a variety of carbonates to the medium significantly increasd the rates of production of succinate. The production of succinate and cell growth were relatively satisfactory in the pH range of 7.0-7.6. By using glycerol as a hydrogen donor, high purity succinate was produced with few byproducts. Yeast extract as a sole nitrogen source was the most effective for producing succinalte. As a result, the optimum condition of biconversion was obtained at a medium containing 20g/I glycerol, 50 g/l fumarate, 15 g/l yeast extract, 10 g/l $K_2HPO_4$, 1 g/I NaCl, 50ppm $MgCl_2{\cdot}6H_2O$, 10ppm $FeSo_4{\cdot}7H_2O$, and 5 g/I $Na_2CO_3$ at pH 7.0-7.6. Under the optimum condition, a succinate concentration of 153 g/I was produced in 36 h. The total volumetric production rate and the molar yield of succinate were 4.3 g/l/h and 85%, respectively.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.137-141
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• 2002

Anabaena variabilis ATCC 29413 grew in chromium (Cr) containing Chu-10 (basal) and nitrate-supplemented media, and the growth of the organism in $100{\mu}M$ chromium was found to be 50% of that in control medium. The growth in nitrate $({NO_3}^-)$ supplemented cultures was better as compared to cultures grown in basal medium. Free cells from basal and nitrate-supplemented media removed 5.2 and 7.4 nmol of chromium $mg^{-1}$protein in 8 h, respectively, from the medium containing $30{\mu}M$ chromium. The efficiency of chromium removal increased 7-fold in imidazole buffer (0.2 M, pH 7.0). A cell density equivalent to $100{\mu}g$ protein $ml^{-1}$ was found to be optimum for maximum Cr removal. Entrapment of cells in calcium-alginate beads did not affect the rate of Cr uptake by the cells. The efficiency of the laboratory-scale continuous flow bioreactor $(12.5{\times}2cm)$ loaded with alginate-immobilized cells (10 mg protein) and fed with $30{\mu}M$ chromium solution was compared at different flow rates. The efficiency of the bioreactor varied with flow rates. In terms of percent removal of Cr from influent, a flow rate of 0.1 ml $min^{-1}$ was found to be optimum for 6 h (54% Cr removal efficiency). Maximum amount of Cr (883 nmol) was removed by the cells in 3 h at a flow rate of 0.5 ml $min^{-1}$. The potential use of A. variabilis in removing Cr from industrial effluents is discussed.