• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.429-434
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• 2000

Isolated protoplasts from ginseng (Panax ginseng C. A. Meyer) callus tissue were cultured in modified MS media supplemented with various concentrations of dimethylsulfoxide (DMSO). The cell wall regeneration rate and cell division efficiency of the protoplasts were increased significantly by 1% DMSO treatment. However, there was no difference in the viability of protoplasts between the DMSO treatment and non-treatment. Transmission electron microscopy revealed that the microtubules were oriented in parallel manner to the plasmalemma after 3 days of culture in medium with 1% DMSO. Further, interconnected cellulose microfibrils were observed on the outer surface of the 3-day-cultured protoplasts by scanning electron microscopy These structures shown by electron microscopy were not observed in protoplasts cultured on DMSO-free media. This studies indicates that DMSO supplemented in culture media seemed to stimulate the cell wall regeneration and cell divisions of protoplasts by forming microtubule organizing centers (MTOC).

• Korean Journal of Plant Tissue Culture
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• v.25 no.6
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• pp.501-505
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• 1998

Conditions for high frequency plant regeneration from cryopreserved embryogenic cell suspension cultures derived from hypocotyl explants of cucumber (Cucumis sativus L.) are described. Cells cryoprotected with a mixture of 2 M DMSO and 0.4 M sucrose exhibited a regeneration frequency of 85%. However, cells cryoprotected with different concentrations of glycerol showed no regeneration after cryopreservation. Pretreatment of cells in a high osmotic medium was not necessary to the process. Upon transfer to MS medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, regenerated calli gave rise to numerous somatic embryos, then underwent development into plantlets.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.7-12
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• 2009

This study was conducted to establish the optimal suspension culture system for both the propagation of embryogenic cells (ECs) and the induction of somatic embryos (SEs) of Kalopanax septemlobus. The proliferation rate of ECs was reduced as the inoculum density was increased; the highest rate was obtained when 0.1 g/100 ml of cells was initially inoculated. According to the analysis of cell growth pattern and cell growth cycle (G1, Sand G2/M), the cell growth started in 5 days culture initiation, grew rapidly until 15 days and then decreased gradually. Distinctive changes of the cell growth cycle by the culture periods was also observed; the growth cycle was doubled from initial 5.6% to 11.7% of S stage in 5 days culture and then reached in stable stages again. Therefore, the results indicated that a 15-day-cycle was the optimal culture period for the propagation of the ECs through the suspension culture. Furthermore, the cell inoculum density was also important for the induction of SE; more than 65% of SEs at the torpedo stage was induced by using the low level of cell inoculum (0.5 g/L), while the higher inoculum densities were rapidly reduced the proportion of SEs at that stage. Although the higher inoculum density delayed the development of SE, it did not affect the proportion of SEs at the globular and heart stage. In conclusion, this study showed that the suspension culture of the Kalopanax septemlobus ECs through the control of inoculum density was an efficient way for both the propagation of ECs and the induction of SEs, suggesting that the development of this system might help to reduce the culture period for the somatic embryo production.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.155-161
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• 2000

This experiment was carried out to examine the effects of culture medium on cell growth of the viola (Viola patrinii DC.) suspension culture. The results are as follows: The greatest cell growth rates were found with MS medium suggesting that this medium could be recommendable for the viola suspension cell culture. When the nitrogen sources (NH$_4$NO$_3$ and KNO$_3$) of MS salts were diluted at half concentrations, the cell growth rates were slightly increased, but when the combined concentration rations of NH$_4$+ and NO$_3$ions were 25 to 75 the greatest cell growth rates were obtained. This result imply that the nitrogen ion sources had slight influence on the rates. Another feature was obtained. This result implys that the nitrogen ion sources had slight influence on the rates. Another feature was that as the concentration of NH$_4$+ ion lowered, the callus color changed to pale yellow with some red spots. The addition of casein hydrolysate (5 g/L) was more effective for the cell growth. On the basis of microscopic observation, the highest cell growth rates were detected during 2-4 weeks culture and after 6 weeks of the culture, some elongated and vacuolated cells were determined.

• Korean Journal of Pharmacognosy
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• v.17 no.4
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• pp.255-262
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• 1986

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.123-123
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• 2005

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.77-77
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• 2000

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.532-535
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• 1988

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.341-345
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• 1995

Seventy four microorganisms, which have antagonistic activity against to Fusarium culmorum, were tested for their inhibitory effect on colony development of obligate biotroph Erysiphe graminis f. sp. hordei Marchal, the causal agent of powdery mildew on barley plants. Of these, 13 actinomycetes isolates were shown to reduce the colony development of mildew completely by application of their 10% cell-free culture filtrates on barley leaves. An Isolate, A252, was the most powerful antagonist and its antifungal activity was further assessed. The colony development of mildew was significantly reduced by application of the 1% cell-free culture filtrate of isolate A252. In comparison to the control, the protective and curative application of 10% cell-free culture filtrate from A252 showed 88.5% and 96.1% reduction of colony numbers respectively. By the protective application, 68.3% of the inhibition was observed after 9 days of treatment, thus showed prolonged inhibitory effect. In vitro test, complete inhibition of the mycelial growth of Microdochium nivale was achieved by the treatment of 1% A252 culture filtrate and 80.2% of inhibition was observed by the 0.1% treatment.

• KSBB Journal
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• v.14 no.5
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• pp.534-538
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• 1999

For the optimization of operating conditions for plant cell suspension culture in bioreactors, effects of bioreactor types, various kinds of impellers, and aeration rates were examined using Nicotiana tabacum cells as a model system. Stirred tank bioreactor and airlift bioreactor were used for the comparison of bioreactor type. Growth rates in both bioreactors were lower than in shake flasks. In terms of final cell concentration, stirred tank bioreactor supported a little bit better growth compared to airlift bioreactor. Impeller type did not affect cell growth significantly, but it was apparent that cell size index decreased in the case of using hollowed paddle impeller. When the aeration rate was maintained at 0.3 vvm, cell growth was the best. At above 1.0 vvm, growth inhibition as well a browning was noticed. In addition, it was found that cell size index reduced proportionally to the increased of aeration rate.