• Journal of Plant Biotechnology
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• 제3권2호
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• pp.107-112
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• 2001

The kinetics of Ti-transformed Salvia miltiorrhiza cell cultures was studied in 250-$m\ell$ shake flasks by using B5 medium with addition of 30 gfL of sucrose. In the cell cultures, the maximum cell mass obtained was 11.5 g DW/L on day 15. The highest amount of phenolic compounds - rosmarinic acid (RA) and lithospermic acid B (LAB) reached 871.3 mg/L (day 15) and 121.3 mg/L (day 13), respectively. The total tanshinone production, i.e., intracellular plus extracellular cryptotanshinone, tanshinone 1, and tanshinone IIA, was 5.3 mg/L on day 13. For the cultivations in 2.4-L stirred bioreactors, the residual sugar level and medium conductivity were a little higher in a small turbine impeller reactor ($T_s$) than those in a large turbine impeller reactor ($T_L$), while a higher cell density was obtained in the $T_L$. For the production of tanshinones and phenolics, better results were obtained in the $T_L$ than in the $T_s$. In the $T_L$, similar or even a little higher production titers of tanshinones and phenolic compounds were achieved compared to those in the flasks. The results suggest that the shake flask results could be successfully scaled up to the $T_L$ reactor. Such a large impeller reactor like $T_L$ may be better than a small impeller one for the large-scale production of the valuable metabolites by the suspension cultures of Ti transformed S.miltiorrhiza cells. This is considered due to the beneficial culture environment in the $T_L$, such as low shear rates as estimated theoretically.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1944-1948
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• 2007

Silkworm hemolymph (SH), prepared from fifth-instar larvae of Bombyx mori and heat-treated at $60^{\circ}C$ for 30 min, was used to improve cell viability and the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic Oryza sativa L. cell suspension cultures. Even though SH could not elevate cell viability at the concentrations up to 3% (v/v), addition of 0.3% (v/v) SH to a culture medium enhanced the production of hCTLA4Ig by 36.8% over an SH-free medium. Moreover, the production period of hCTLA4Ig could be shortened in a 0.3% (v/v) SH-added medium compared with that in an SH-free culture. As a result, addition of 0.3% (v/v) SH improved the productivity of hCTLA4Ig significantly in transgenic rice cell cultures.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.117-120
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• 2002

The effect of cell density on cell growth was investigated in a suspension batch culture of hybridoma cells. The specific growth rate was found to increase with increasing initial cell density and then to decrease with further increases in initial cell density. In order to quantitatively describe the dependence of specific growth rate on cell density, a kinetic model is proposed, which satisfactorily represents the experimental data.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.135-141
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• 2003

The human granulocyte-macrophage colony stimulating factor (hGM-CSF) gene was introduced into tobacco plants. The cell suspension culture was established from leaf-derived calli of the transgenic tobacco plants in order to express and secrete a biologically active hGM -CSF. The recombinant hGM-CSF from the transgenic plant cell culture (prhGM-CSF) was identified as a yield of about 180 ${\mu}$g/L in the culture filtrate, as determined by ELISA. The addition of 0.5 g/L polyvinylpyrrolidone (PVP) to the plant cell culture medium both stabilized the secreted prhGM-CSF and increased the level of production approximately 1.5-fold to 270 ${\mu}$g/L. The biological activity of the prhGM-CSF was confirmed by measuring the proliferation of the hGM-CSF-dependent cell line, TF-1. Interestingly, the specific activity of the prhGM-CSF was estimated to be approximately 2.7 times higher than that of a commercially available preparation from E. coli.

• KSBB Journal
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• 제11권5호
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• pp.600-605
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• 1996

Taxus brevifolia와 Taxus cuspidata 현탁세포배 양에서 taxa!의 생산에 가장 적합한 초기 접종농도 를 결정하기 위해 접종농도를 세포생체중량으로 2.5, 5 5, 7.5, 10 g/flask가 되도록 변화시켜 세포의 생장 과 taxol의 생산을 측정하였다. Taxus brevifolia의 경우 초기 접종농도가 높을수록 lag phase가 감소되 는 경향을 보였으며, 두 가지 세포주(Taxus bre­1 vifolia와 Taxus cuspidata)에서 모두 초기 접종농도 를 5 g/flask가 taxol의 생산에 최척 임을 확인할 수 있었다. Taxol 생산에 가장 척합한 초기 접종농도로 생장배지와 생산배지에 세포를 접종시켰을 때 생장 배지에서는 taxal이 검출되지 않았지만 6% 자당을 이용한 생산배지에서는 9일째 taxol이 최대로 생산 되었다가 이후 다시 줄어드는 경향을 보였다.

• KSBB Journal
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• 제4권3호
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• pp.271-275
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• 1989

본 논문에서는 Thalictrum rugosum 식물세포의 회분식 배양에 있어서 동역학적 특성들을 연구하였다. 본 실험에서 alkaloid의 생성은 일반적인 2차대사 산물의 생성 특성과 달리 세포성장에 비례함이 확인되었다. 세포 성장기의 비증식속도는 $0.20~0.25\;day\;^{-1}이었으며 FW / DCW 비가 배양상태를 나타내는 중요한 인자임을 알수 있었다. Cell yield는 0.36g cells/g sugar이었으며 berberine은 139mg/L까지 생성되었고 그중 120mg/L는 세포내에 존재하였다. 이를 specific content로 계산하면 dry cell weight의 1.10%가 된다. 세포 성장기에서 비증식속도와 당농도간의 관계는 Monod kinetics로 잘 기술될 수 있었다.

• BMB Reports
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• 제57권6호
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• pp.273-280
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• 2024

Cancer cells metastasize to distant organs by altering their characteristics within the tumor microenvironment (TME) to effectively overcome challenges during the multistep tumorigenesis. Plasticity endows cancer cell with the capacity to shift between different morphological states to invade, disseminate, and seed metastasis. The epithelial-to-mesenchymal transition (EMT) is a theory derived from tissue biopsy, which explains the acquisition of EMT transcription factors (TFs) that convey mesenchymal features during cancer migration and invasion. On the other hand, adherent-to-suspension transition (AST) is an emerging theory derived from liquid biopsy, which describes the acquisition of hematopoietic features by AST-TFs that reprograms anchorage dependency during the dissemination of circulating tumor cells (CTCs). The induction and plasticity of EMT and AST dynamically reprogram cell-cell interaction and cell-matrix interaction during cancer dissemination and colonization. Here, we review the mechanisms governing cellular plasticity of AST and EMT during the metastatic cascade and discuss therapeutic challenges posed by these two morphological adaptations to provide insights for establishing new therapeutic interventions.

• Journal of Plant Biology
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• 제33권2호
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• pp.87-96
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• 1990

The role of S-adenosylmethionine (SAM) as an intermediate in interrelation between polyamine and ethylene biosynthesis was studied in suspension cultures of Nicotiana tabacum L. Exogenous SAM stimulated the polyamine and ethylene biosynthesis in 4 day-cultured cells, which were in active cell divisions, and 10 day cultured cells, which went on with active cell elongation and senescence. SAM-induced ethylene production was more effective in 10 day-cultured cells than in 4 day-cultured cells, but SAM-induced polyamine biosynthesis was more effective in 4 day-cultured cells than in 10 day-cultured cells. Polyamine contents were increased by the blockage of ethylene biosynthetic pathway in the conversion of SAM to ethylene via 1-aminocyclopropane-1-carboxylinc acid (ACC) with aminooxyacetic acid (AOA). Also, ethylene production was increased by the inhibitors of polyamine biosynthesis such as methylglyoxal bis-(guanylhydrazone) (MGBG), dicyclohexylamine (DCHA), $\alpha$-difluoromethylarginine (DFMA) and $\alpha$-difluoromethylorinithine (DFMO). These results suggest that there may be interrelations between polyamine and ethylene biosynthesis for the competition of SAM and the inherent mechanism of switch on-off in polyamine and ethylene biosynthetic activity with the progress of cell growth and senescence.

• Journal of Plant Biology
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• 제34권1호
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• pp.19-23
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• 1991

벼의 종자로부터 embryogenic callus를 유도하고 이로부터 개체로의 재분화를 유도하였으며, embroyogenic cell suspension culture를 통하여, 이로부터 원형질체를 분리, 배양하여 embryogenic callus를 형성하였다. 또한, 분리된 원형질체를 electroporation하였을 때 생존율(viability)에 미치는 여러 요인들을 조사하였다. 원형질체의 생존율은 voltage와 capactiance가 증가할수록 감소를 보였으며, HBM buffer에서 $4^{\circ}C$로 electroporation 하였을 때 생존율에 보다 효과적이었다.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.238-243
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• 1993

In the suspension cultures of Eschscholtzia californica, phytohormone effects showed that alkaloid production was increased by IAA treatment without kinetin in both volumetric and specific way. Kinetin, however, suppressed alkaloid accumulation. Addition of ethephon inhibited cell growth. However, it enhanced the alkaloid production significantly in both volumetric and specific way. IAA promoted alkaloid production during elicitation. The highest alkaloid accumulation was observed at 5 $\mu$ M of IAA. Ethephon also enhanced alkaloid production during elicitation. The highest alkaloid formation was observed at 460 mg/l of ethephon with elicitation. Elicitation with ethephon, however, altered cell growth and the pattern of benzophenanthridine alkaloids production.