• Journal of Plant Biotechnology
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• 제36권4호
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• pp.309-319
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• 2009

Transgenic plant cell cultures for the production of biopharmaceuticals including monoclonal antibodies, recombinant proteins have been regarded as an alternative platform in addition to traditional microbial fermentation and mammalian cell cultures. Plant-made pharmaceuticals (PMPs) have several advantages such as safety, cost-effectiveness, scalability and possibility of complex post-translational modifications. Increasing demand for the quantity and diversity of pharmaceutical proteins may accelerate the industrialization of PMP technology. Up to date, there is no plant-made recombinant protein approved by USFDA (Food and Drug Administration) for human therapeutic uses due to the technological bottlenecks of low expression level and slight differences in glycosylation. Regarding expression levels, it is possible to improve the productivity by using stronger promoter and optimizing culture processes. In terms of glycosylation, humanization has been attempted in many ways to reduce immune responses and to enhance the efficacy as well as stability. In this review article, all these respects of transgenic plant cell cultures were summarized. In addition, we also discuss the general characteristics of plant cell suspension cultures related with bioreactor design and operation to achieve high productivity in large scale which could be a key to successful commercialization of PMPs.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.72-74
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• 2001

Transgenic Nicotiana tabacum cells were cultivated for the production of murine granulocyte macrophage-colony stimulating factor (mGM-CSF) in both a stirred tank bioreactor and an airlift bioreactor with draft tube. Cell growth and mGM-CSF production in the airlift bioreactor were found to be better than those achieved in the stirred tank bioreactor. In the airlift bioreactor, 9.0g/L of cells and 2.2ng/mL of mGM-CSF were obtained (11.0g/L and 2.4ng/mL, respectively in shake flasks). Although the lag period was prolonged and mGM-CSF production was lowered by 33% in the stirred thank bioreactor as compared to the control culture, the maximum cell density was increased up to 12.0g/L due to better mixing by agitation at the higher cell density.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2006년도 한국약용작물학회 공동춘계학술발표회
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• pp.422-423
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• 2006

• Plant Biotechnology Reports
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• 제4권1호
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• pp.9-13
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• 2010

Guggulsterone, a hypolipidemic natural agent, is produced in resin canals of the plant Commiphora wightii. In this study, the stimulatory effects of growth retardants [ALAR (N,N-dimethylaminosuccinamic acid) and CCC (chlormequat chloride)] and fungal elicitor on guggulsterone accumulation in cell cultures of C. wightii are reported. CCC at $1\;mg\;l^{-1}$ enhanced guggulsterone content (${\sim}123\;{\mu}g\;l^{-1})$ when added on the fifth day after inoculation, while ALAR at $2.5\;{\mu}g\;l^{-1}$ increased guggulsterone content (${\sim}116\;{\mu}g\;l^{-1}$) when added on the tenth day. In a two-stage fed-batch process, combined treatment with fungal elicitor and growth retardant caused a significant increase (${\sim}353\;{\mu}g\;l^{-1}$) in guggulsterone content in cell cultures after 17 days of growth. This represents an approximately fivefold increase over the guggulsterone contents in initial cultures of this plant.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.968-975
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• 2018

In the course of screening for microbes with nematicidal activity, we found that Enterobacter asburiae HK169 displayed promising nematicidal activity against the root-knot nematode Meloidogyne incognita, along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of M. incognita within 48 h. In addition, the nematicidal activity of the culture filtrate was dramatically reduced by a protease inhibitor, suggesting that proteolytic enzymes contribute to the nematicidal activity of HK169. In order to obtain genomic information about the HK169 isolate related to its nematicidal and plant growth-promoting activities, we sequenced and analyzed the whole genome of the HK169 isolate, and the resulting information provided evidence that the HK169 isolate has nematicidal and plant growth-promoting activities. Taken together, these observations enable the future application of E. asburiae HK169 as a biocontrol agent for nematode control and promote our understanding of the beneficial interactions between E. asburiae HK169 and plants.

• Journal of Plant Biotechnology
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• 제6권4호
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• pp.265-268
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• 2004

Cell growth and ginseng saponin production by large-scale suspension (bioreactor) cultures of Panax ginseng were investigated under various inoculum sizes. Cell growth was low at an inoculum size of 40 g FW/L, and the maximum cell growth was obtained with increasing inoculum size up to 100 g FW/L. The cell density of 333 g FW/L and 12.7 g DW/L was obtained at inoculum size of 100 g FW/L after 30 days of cultivation. Maximum saponin production of $4.40\;\cal{mg/g}$ DW was achieved at 60 g FW/L of inoculum size. Thus, inoculum size 60 g FW/L was suitable for optimum biomass accumulation as well as saponin production during bioreactor cultivation of ginseng suspension cells.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.73-77
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• 2005

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration in P. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture of P. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor and D-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at $1\%$ (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.132-136
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• 1996

To investigate the characteristics of immobilized peppermint (Mentha piperita) cells, dry cell weight (DCW), change of cell viability, and oil productivity of the immobilized cells were determined. Peppermint cells were immobilized in polyurethane (PU) foams of $5{\times}5{\times}5$ mm and cultured in a shaking flask. The maximum DCW was 2.1 mg per foam piece after 20 days of cultivation and the cell density was approximately 420 mg per flask containing 200 foams in 200 ml medium. For the first five days of cultivation, the cell viability was about 80$%$ and decreased to 70$%$ during 5 to 20 days of cultivation. The maximum oil productivity, 148 mg/l was achieved after 40 days of cultivation. The immobilized cells were also cultivated in a bioreactor, equipped with a round spiral type impeller, containing 2, 400 PU foams. The cell viability after 30 days of cultivation with chitosan as an elicitor in the bioreactor was 67$%$ and DCW was 2.0 mg per foam piece. Though the cell viability was relatively high in the bioreactor system, the oil productivity was relatively lower than that of the flask system.

• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.309-314
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• 1995

Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

• 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.