• Journal of Plant Biotechnology
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• 제35권2호
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• pp.127-132
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• 2008

In bioreactor cultures of plants, inoculum density is an important factor affecting growth and proliferation of the plantlets. To maximize shoot growth and proliferation of grape rootstock '5BB' in bioreactors, inoculum density varied at 15, 30, 45 and 60 single nodes in a 3-liter scale balloon type bioreactor, respectively and cultured for 40 days. Results suggested that the growth and the photosynthesis of the plantlet were greatly affected by inoculum density in the bioreactor. The inoculum density of 45 nodes resulted in the greatest growth (910.4 mg/shoot FW, 764.4 mg/root FW) followed by 30 nodes. $CO_2$ assimilation rate, stomatal conductance, transpiration rate of the plantlet were also highest at the inoculum density of 45 nodes. Significant reduces in shoot and root growth (426.5 mg/shoot FW, 248.4 mg/root FW) were observed at the inoculum density of 60 nodes. When the inoculum density decreased by 15 nodes, plantlets were malformed due to hyperhydricity, resulting in the highest transpiration rate and the lowest $CO_2$ assimilation rate. The plantlets stressed by the inoculum density at 15 nodes and 60 nodes showed larger number and irregular shape of stomata compared to the plantlets inoculated with 45 nodes.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1071-1078
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• 2007

Using a 50-1 airlift bioreactor, for the effective production of tylosin from Streptomyces fradiae TM-224 using raw cornmeal as the energy source, various environmental factors were studied in flask cultures. The maximum tylosin concentration was obtained at $32^{\circ}C$ and pH between 7.0 and 7.5. When seed was inoculated after 24 h of culture, the maximum tylosin concentration, 5.7 g/l, was obtained after 4 days of culture. Various concentrations of raw cornmeal were tested to investigate the optimum initial concentration for the tylosin production. An initial raw cornmeal concentration of 80 g/l gave the highest tylosin concentration, 5.8 g/l, after 5 days of culture. Of the various nitrogen sources, soybean meal and fish meal were found to be the most effective for the production of tylosin. In particular, with the optimal mixing ratio, 12 g/l of soybean meal to 14 g/l of fish meal, 7.2 g/l of tylosin was obtained after 5 days of culture. To compare raw cornmeal and glucose for the production of tylosin in the 50-1 airlift bioreactor for 10 days, fed-batch cultures were carried out under the optimum culture conditions. When raw com meal was used as the energy source, the tylosin production increased with increasing culture time. The maximum tylosin concentration after 10 days of culture was 13.5 g/l, with a product yield from raw cornmeal of 0.123 g/g of consumed carbon source, which was about 7.2 times higher than that obtained when glucose was used as the carbon source.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1281-1287
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• 2017

Bone morphogenetic protein-4 (BMP-4) is considered to have therapeutic potential for various diseases, including cancers; however, the high expression of biologically active recombinant human BMP-4 (rhBMP-4) needed for its manufacture for therapeutic purposes has yet to be established. In the current study, we established a recombinant Chinese hamster ovary (rCHO) cell line overexpressing rhBMP-4 as well as a production process using 7.5-l bioreactor (5 L working volume). The expression of the mature rhBMP-4 was significantly enhanced by recombinant furin expression. The combination of a chemically defined medium and a nutrient supplement solution for high expression of rhBMP-4 was selected and used for bioreactor cultures. The 11-day fed-batch cultures of the established rhBMP-4-expressing rCHO cells in the 7.5-L bioreactor produced approximately 32 mg/l of rhBMP-4. The mature rhBMP-4 was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure, resulting in a recovery rate of approximately 55% and a protein purity greater than 95%. The N-terminal amino acid sequences and N-linked glycosylation of the purified rhBMP-4 were confirmed by N-terminal sequencing and de-N-glycosylation analysis, respectively. The mature purified rhBMP-4 has been proved to be functionally active, with an effective dose concentration of $EC_{50}$ of 2.93 ng/ml.

• 한국균학회지
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• 제35권1호
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• pp.37-42
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• 2007

잣버섯 균사체 배양에 적합한 생물반응기는 풍선형의 공기부양식의 생물반응기가, 수용성 다당체의 생산에도 생장이 좋았던 풍선형 공기부양식 생물반응기가 유리한 것으로 나타났다. 배지의 탄소원 농도별에 따른 수용성 세포외 다당체의 생산량은 농도 처리간 차이가 없었으나 수용성 세포내 다당체는 탄소원 농도가 낮은 즉 C/N율이 낮을수록 증가하였다. 잣버섯 균사체는 고농도의 배지 배양조건에서 생물반응기내로 배지 공급형태가 배지량 증가방법보다 배지농도 조절에 의한 연속 배양방법이 우수한 것으로 나타났다.

• KSBB Journal
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• 제13권3호
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• pp.268-271
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• 1998

Bacteriorhodopsin in the purple membrane (PM) of halobacteria has recently been attracting much attention to be used as a component of molecular electron device and optical computers. In order to increase the productivity of bacteriorhodopsin in high cell density cultures of Halobacterium halobium R1, an internal membrane cell-retention bioreactor system was employed. As a result, the production of cell mass at OD660 of 12 and of bacteriorhodopsin at 125-130 mg/L were obtained using the internal membrane bioreactor system at a dilution rate of 0.066 hr-1. The productivity achieved by the internal membrane system (0.7 mg/L$.$hr) was 3.5-fold higher than that obtained by the corresponding batch cultivations (0.2 mg/L$.$hr).

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.673-677
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• 2006

A perfusion culture of transgenic Nicotiana tabacum cell suspensions, transformed to express recombinant glucuronidase (GUS), was successfully performed in a 5-1 stirred tank bioreactor. With 0.1 $day^{-1}$ of perfusion rate, the maximum dry cell weight (DCW) reached to 29.5 g/l in 16 days, which was 2.1-fold higher than the obtained in batch culture (14.3 g/l). In terms of the production of GUS, the volumetric activity could be increased up to 12.8 U/ml by using perfusion, compared with 4.9 U/ml in batch culture. The specific GUS activities in both perfusion and batch cultures were maintained at similar levels, 200-400 U/g DCW. Consequently, a perfusion culture could be a good strategy for the enhanced production of recombinant proteins in a plant cell culture system.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.162-165
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• 2005

A series of fluorine and hydroxyl containing jasmonate derivatives, which were chemically synthesized in our institute, were investigated for their effects on the biosynthesis and heterogeneity of ginsenosides in suspension cultures of Panax notoginseng cells. Com-pared to the control (without addition of elicitors), $100{\mu}M$ of each of the jasmonate was added on day 4 to the suspension cultures of P. notoginseng cells. It was observed that, jasmonates greatly enhanced the ginsenoside content and the ratio of Rb group to Rg group (i.e. $(Rb_1\;+\;Rd)/(Rg_1\;+\;Re)$ in the P. notoginseng cells. Some of the synthetic jasmonates, such as pentafluoropropyl jasmonate (PFPJA), 2-hydroxyethyl jasmonate (HEJA) and 2-hydroxye-thoxyethyl jasmonate (HEEJA), could promote the ginsenoside content to $2.55\;\pm\;0.11,\;3.65\;\pm\;0.13\;and\;2.94\;\pm\;0.06$mg/100 mg DW, respectively, compared to that of $0.64\;\pm\;0.06$mg/100 mg DW for the control and $2.17\;\pm\;0.04$ mg/100 mg DW by the commercially available methyl jasmonate (MJA); and they could change the respective Rb:Rg ratio to $1.60\;\pm\;0.04,\;1.87\;\pm\;0.01\;and\;1.56\;\pm\;0.05$, compared to that of $0.47\;\pm\;0.01$ for the control and $1.42\;\pm\;0.06$ by MJA. The results suggest that suitable esterification of MJA with fluorine or hydroxyl group could in-crease the elicitation activity to induce plant secondary metabolism. The information obtained from this study is useful for hyper-production of heterogeneous products by plant cell cultures.

• Journal of Plant Biotechnology
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• 제3권1호
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• pp.1-5
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• 2001

Traditional culture technology of medicinal plants mainly depends on the field culture, which has many problems. With progress of modern culture technology, it has become possible to produce valuable secondary metabolites from medicinal plants. In this paper, we discuss about the pigment and saikosaponin production from too medicinal plants, Carthamus tinctorius and Bupleurum falcatum, through bioreactor culture system. A two-stage bioreactor culture system was established for the production of yellow and red pigments and saikosaponins by cell suspension cultures of Carthamus tinctorius and Bupleurum falcatum. In Carthamus tinctorius, balloon type airlift bioreactors and column type airlift bioreactors were employed for the tell culture and for the pigment production, respectively. The greatest pigment production was obtained on White medium supplemented with 4 mg/L kinetin, high levels of sucrose concentration and photosynthetic photon flux. In Bupleurum falcatum, adventitious roots were cultured in balloon type airlift bioreactors and the root growth was greatest on SH medium containing 5 mg/L IBA and 0.2 mg/L kinetin. HPLC analysis showed that the contents of main active saikosaponins a, c, and d in adventitious roots were almost the same as those in field cultured root.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.288-305
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• 2000

A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects-the basics of yeast flocculation, the development of "new" flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer's yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous $\beta$-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculating bioreactors and discussing potential new uses of these systems.e systems.