• 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.

• Journal of Life Science
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• v.9 no.4
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• pp.408-413
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• 1999

Extracellular capsidiol, sesquiterpenoid phytoalexin, in the medium of pepper (Capsicum annuum L.) suspension cells was not identified from control cells, but highly accumulated in the elicitor-induced cells within 6 hours after the addition of 0.05$\mu\textrm{g}$/$m\ell$ cellulase. Capsidiol production in elicitor-induced cells was markedly suppressed by cytochrome P450 inhibitors, such as ancymidol and ketoconazole demonstrating that biosynthesis of capsidiol is catalyzed by at least on hydroxylation enzyme in the biochemical pathway. Based on protein electrophoresis, two bands, 23.0kDa and 27.5kDa, were identified as newly synthesized polypeptides in the elicitor-induced suspension cells, suggesting that pepper cells which were subjected to elicitor treatment activate specific gene(s) for capsidiol biosynthesis in cultured cells.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.449-454
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• 2000

The heavy chain monoclonal antibody (HC MAb) was produced in suspension cultures of genetically modified Nicotiana tabacum. The HC MAb secreted to the medium was unstable due to unfavorable interactions in the plant cell medium. The addition of gelatin (5g/l) stabilized the extracellular HC MAb and increased its production 10-fold. A kinetic model was developed describing the interaction between the secretedprotein and the stabilizer. The model accounted for the inactivation of the protein by simple aggregation and general instability. It was assumed that the secreted protein and the stabilizer form a stable complex. Culturing the cells semicontinuously could further increase the productivity of HC MAb.

• KSBB Journal
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• v.17 no.1
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• pp.110-113
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• 2002

Studies were made to examine the various effects of jasmonic acid and benzoic acid on ginsenoside production in suspension cultures of Panax ginseng C. A. Meyer. Jasmonic acid increased the ginsenoside production when it was dosed at the concentration of 50 $\mu$M or higher. The cell growth, however, was reduced with jasmonic acid. When benzoic acid was dosed simultaneously with iasmonic acid, the ginsenoside production increased 9.6 folds. It was 2.2 times higher than the result of single dose of jasmonic acid.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.239-248
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• 2004

This experiment was carried out to confirm that phytochrome regulates anthocyanin bio-synthesis during cell suspension culture system of grape or not. In suspension culture of grape, maximum accumulation of anthocyanin was observed at the stationary phase under continuous white light condition. From mono-chromatic light interruption for 24h at the 4th or 7th day on the suspension cultured cells, the anthocyanin accumulation was highly enhanced at the light interruption at 7th day than 4th day under all monochromatic light treatment. However, the cell growth patterns were not affected by any light treatment. In the darkness, the anthocyanin synthesis was very low but remarkably increased by blue light or red light irradiation. However, the increase of anthocyanin accumulation by blue or red light was suppressed by far-red light in the suspension cells of grape. This suppression by far-red light on the anthocyanin synthesis also observed on the cells treated red or far-red light alternatively. These results implied that phytochrome regulation system may be involved in the anthocyanin biosynthesis of the suspension grape cells. By RNA expression analysis, chalcone synthase (CHS) gene was expressed highly by blue and red light but low by far-red light. The synergistic increase of CHS gene expression was also observed at the treatment of blue light followed by red for 24h. This result may explain the increase of anthocyanin accumulation in B/R treatment. Although the expression of phytochrome gene (PHYA or PHYB) was not highly increased by all light treatment (blue, red, and far-red light) the expression of both PHYA gene and PHYB gene was increased a little in cells treated red or far-red light. In grape suspension cells, the red light enhanced the anthocyanin synthesis, whereas the far-red light was suppressed. Although it was not confirmed whether or not phytochrome gene is activated in anthocyanin accumulating grape cells, we believed that anthocyanin biosynthesis in grape cells may be regulated under phytochrome signal transduction system.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.160-160
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• 2002

• KSBB Journal
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• v.13 no.2
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• pp.181-186
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• 1998

In order to obtain high-level production of recombinant human thrombopoietin (rhTPO) in insect cell line, HTI-TN-5B1-4 (TN5), conditions for optimal rhTPO expression such as multiplicity of infection (MOI), the cell density at infection, harvesting time and type of culture method as well as growth media were determined. When TN5 cells were cultured as anchorage-dependent state in 60-mm dish, cell density $2\times^6$ cells,MOI of 10 and Garvesting the culture media at 72 hr post-infection wrere the cinditions for highest rh TPO production. High production of rhTPO was also achieved by using EXPRESS FIVE serum free media rather than SF900II serum free media-1. Anchorage-dependent TN5 cells were adapted as a suspension culture when they were grown in the presence of heparin. TN5 cells were successfully cultured at 0.2 L scale in suspension culture without having aggregation. When TN5 cells were cultured as suspension state, cell density of $0.6\times10^6$ cells/mL, MOI of 1 and harvesting the culture media at 72 hr post-infection, gave the highest yield of rhTPO.

• KSBB Journal
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• v.16 no.6
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• pp.620-625
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• 2001

This study was examined to investigate the time course behaviors of cell growth and sucrose consumption, and effects of various elicitors on ginsenoside production in batch suspension cultures of Panax ginseng Meyer. Suspended cells reached to the stationary phase at 12 days after innoculation. The maximum cell concentration was 14.7 g-DCW/L at 17 days. The highest cell growth rate was 0.59 g-DCW/L d. The sucrose used as a sole carbon source was hydrolysed to glucose and fructose in 4 days, then quickly utilized until the middle-log phase and consumpted completely at 16 days. Various elicitors were app1ied at 8 days from inoculation which is the middle-log phase. Among the elicitors tested, jasmonic acid was the most efficient to increase the ginseneside production, which was 1.5 times higher than control.

• Journal of Plant Biotechnology
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• v.4 no.4
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• pp.143-150
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• 2002

A strong oxidative stress-inducible peroxidase promoter (referred to as SWPA2 promoter) was cloned from tell cultures of sweetpotato (Ipomoea batatas) and characterized in transgenic tobacco cultured cells in terms of biotechnological applications. Employing a transient expression assay in tobacco protoplasts, with five different 5'-deletion mutants of the SWPA2 promoter fused to the $\beta$-glucuronidase (GUS) reporter gene, the 1314 bp deletion mutant showed approximately 30 times higher GUS expression than the CaMV 35S promoter. The expression of GUS activity in suspension cultures of transgenic cells derived from transgenic tobacco leaves containing the -1314 bp SWPA2 promoter-GUS fusion was strongly expressed following 15 days of subculture compared to other deletion mutants, suggesting that the 1314 bp SWPA2 promoter will be biotechnologically useful for the development of transgenic cell lines engineered to produce key pharmaceutical proteins. In this respect, we developed transgenic cell lines such as tobacco (Nicotiana tabacum L. BY-2), ginseng (Panax ginseng) and Siberian ginseng (Acanthopanax senticosus) using a SWPA2 promoter to produce a human lactoferrin (hLf) and characterized the hLf production in cultured cells. The hLf production monitored by ELISA analysis in transgenic BY-2 cells was directly increased proportional to cell growth and reached a maximal level (up to 4.3% of total soluble protein) at the stationary phase in suspension cultures. The SWPA2 promoter should result in higher productivity and increased applications of plant cultured cells for the production of high-value recombinant proteins.

• KSBB Journal
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• v.14 no.6
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• pp.665-671
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• 1999

In this study, enhanced production of 10-deacetylbaccatin III(10-DAB), a precursor of taxol in semisynthesis, was investigated in Taxus cuspidata cell suspension cultures. The effects of initial inoculum size and sugar concentration were examined to prove the relationship between the production of 10-DAB and cell growth. The cell growth was found to be stimulated in Schenk and Hildebrandt(SH) medium. The lower the inoculum size as well as initial sugar concentration, the faster the cell growth rate. When the initial sugar concentration was dept low, the production of 10-DAB into medium was increased. By using perfusion culture, continuous cell growth was possible until the end of culture and more than 34.67 g/L of cell concentration could by obtained. This is about 2.5 times higher level than that of control batch culture.