• KSBB Journal
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• v.15 no.5
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• pp.489-496
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• 2000

Several culture systems including batch, two-stage CSTR, semi-fed batch, and two-stage cyclic fed-batch were investigated for the efficient production of the Fab fraction of PDC-E2 specific human monoclonal antibody using high cell density recombinant E. coli. A two-phase batch system and a two-stage continuous system were examined to overcome plasmid instability problems, by separating the growth and the production stages. The cell density and productivity of the two-stage continuous culture was better than that of the two-phase batch fermentation. In the two-stage continuous culture system with DO-stat, the cell growth and the productivity were superior to those of the system without the DO control. Also, almost total plasmid stability was maintained in the two-stage continuous culture system. Modified M9 medium was selected as an optimum feeding medium for the fed-batch process, and the optimum C/N ratio determined to be 2:3. The optimum feeding rate was $0.6g/\ell/hr$ for a constant feeding strategy in semi-fed batch system. When the feeding medium was fed by pulsing, it was observed that more frequent pulsing resulted in improved cell growth. The linear feeding method was the most efficient of the various feeding methods tested. Finally, high cell density culture using a two-stage cyclic fed batch system with pH-stat was tried because the linear feeding method showed limitations in terms of obtaining high cell densities, and a cell density of $54 g/\ell$ was achieved. It was concluded that the two-stage cyclic fed batch system was the most efficient system for high cell density culture of the systems tested. However, productivity improvements were lower than expected due to the extremely high accumulations of acetate, although the low levels of residual glucose were maintained.

• Journal of Environmental Science International
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• v.30 no.8
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• pp.685-691
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• 2021

This study aimed to find a suitable size and a seedling raising stage for growing cuttings of Euonymus fortunei 'Emerald and Gold' using plug trays. The experimental method, involved cutting two nodes from a solitary branch of E. fortunei 'Emerald and Gold', and the use of 32 (143 mL/cell), 50 (70 mL/cell), 105 (18 mL/cell), 200 (13 mL/cell) plug trays. The cuttings were transplanted to trays after they were filled with a universal horticultural medium. To compare the growths, plant heights, the numbers of leaves, longest root lengths, thickness/radius ratios, dry weights, and fresh weights were measured from July to October, and statistical analyses were performed using both the two-way repeated-measures analysis of variance (ANOVA) and Tukey's post-test. The results confirmed that the size of the plug tray and the seedling raising stage had a significant effect on the growth of E. fortunei 'Emerald and Gold.' In addition, the overall growth was high and the change in growth was relatively rapid in districts 50 and 105. Therefore, it can be considered appropriate to use 50 and 105 trays when growing cuttings of E. fortunei 'Emerald and Gold' on plug trays.

• Development and Reproduction
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• v.14 no.2
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• pp.131-141
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• 2010

This study was conducted to examine the hematological factors in cultured olive flounder Paralichthys olivaceus depending on its growth stage and season. The study also aims at developing the standard hematological indicator for growth stage and season by examining total 16 parameters including whole blood (hematocrit, red blood cell and hemoglobin), biochemical (glucose, cholesterol, total protein, AST, ALT, $Na^+,\;K^+,\;Cl^-,\;Ca^{2+},\;Mg^{2+}$ and osmolarity), and endocrine (cortisol and $T_3$) factors in plasma of cultured olive flounder. The result showed a growth stage-dependent increase of $T_3$ level in olive flounder while the level of cholesterol showed an inverse correlation to fish size. For seasonal fluctuation in cultured olive flounder of the same growth stage, the highest level of Ht and RBC was observed in autumn.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.932-937
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• 2004

In situ extraction by organic solvent was studied in order to improve the recovery yield of hydrocarbon from the culture of Botryococcus braunii, a green colonial microalga. When the solvent mixture of octanol as an extractive solvent and n-octane as a biocompatible solvent was added to a two-phase column, the algal growth was seriously inhibited, even at a low concentration of polar octanol. Therefore, a two-stage cell-recycle extraction process was proposed to improve the contact area between the organic phase and the aqueous phase. The hydrocarbon recovery with in situ cell-recycle extraction showed a three-fold increase (57% of cell) in yield over that with two-phase extraction. In addition, over 60% of the hydrocarbon could be recovered without serious cell damage by downstream separation when this process was applied to the culture broth after batch fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.935-940
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• 2001

To determine the effect of different growth stages and cultivars on the chemical composition of sorghum plant and its morphological fractions, samples of whole plant, leaf and stem of J.S-263, J.S-88 and Hegari cultivars, harvested at various growth stages were drawn for analysis. All the samples were analysed for their dry matter contents and various cell wall components such as NDF, ADF. hemicellulose, cellulose, lignin, cutin and silica. Significant increase in DM contents of whole sorghum plant, leaf and stem was observed with advancing stage of growth. The highest DM content was recorded in leaf fraction of the plant. All the cell wall constituents increased significantly in whole sorghum plant, leaf and stem as the plant matured. The maximum NDF, ADF, cellulose and lignin contents were observed in stem fraction, followed by whole plant. However, the hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were found to have some effect on the chemical composition of whole plant, leaf and stem fractions. The results indicated that plant maturity had a much greater effect on the chemical composition of sorghum plant, whereas it was little affected by cultivars.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.77-86
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• 1998

The uptake of glucose for metabolism and growth is essential to most animal cells and is mediated by glucose-transporter (GLUT) proteins. The aim of this study was to determine which class of glucose transporter molecules was responsible for uptake of glucose in the mouse early embryo and at which stage the corresponding genes were expressed. In addition, co-culture system with vero cell was used to investigate the effect of the system on GLUT expression. Two-cell stage embryos were collected from the superovulated ICR female and divided into 3 groups. As a control, embryos were cultured in 0.4% BSA-T6 medium which includes glucose. For the experimental groups, embryos were cultured in either co-culture system with vero cells or glucose-free T6 medium supplemented with 0.4% BSA and pyruvate as an energy substrate. 2-cell to blastocyst stage embryos in those groups were respectively collected into microtubes (50 embryos/tube). Total RNA was extracted and RT-PCR was performed. The products were analysed after staining ethidium bromide by 2% agarose gel electrophoresis. Blastocysts were collected from each group at l20hr after hCG injection. They were fixed in 2.5% glutaraldehyde, stained with hoechst, and mounted for observation. In control, GLUT1 was expressed from 4-cell to blastocyst. GLUT2 and GLUT3 were expressed in morula and blastocyst. GLUT4 was expressed in all stages. When embryos were cultured in glucose-free medium, no significant difference was shown in the expression of GLUT1, 2 and 3, compared to control. However GLUT4 was not expressed until morular stage. When embryos were co-cultured with vero cell, there was no significant difference in the expression of GLUT1, 2, 3 and 4 compared to control. To determine cell growth of embryos, the average cell number of blastocyst was counted. The cell number of co-culture ($93.8{\pm}3.1$, n=35) is significantly higher than that of control and glucose-free group ($76.6{\pm}3.8$, n=35 and $68.2{\pm}4.3$, n=30). This study shows that the GLUT genes are expressed differently according to embryo stage. GLUTs were detectable throughout mouse preimplantation development in control and co-culture groups. However, GLUT4 was not detected from 2- to 8-cell stage but detected from morula stage in glucose-free medium, suggested that GLUT genes are expressed autocrinally in the embryo regardless of the presence of glucose as an energy substrate. In addition, co-culture system can increase the cell count of blastocyst but not improve the expression of GLUT. In conclusion, expression of GLUT is dependent on embryo stage in preimplantation embryo development.

• 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.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.29-29
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• 2001

This study was carried out to examine, by the reverse transcription chain reaction(RT-PCR)and Immunostain assays, epidermal growth factor mRNA expression in bovine ova during oocyte maturation in vitro(0-2lh)and after fertilization in vitro(6-144hr: zygotes to blastocysts). In this study, the transcripts of EGF was detected in oocytes using primers for EGF. Transcripts for EGF mRNA was not detected in oocytes through in vitro maturation. But EGF mRNA were present after fertilization up to the 2-cell stage and the blastocyst stage. The highest mRNA levels in 4-cell stage embryos were decreased at 8cell stage and then reincreased upto morulae and blastocysts. The results of this study showed EGF mRNA are present in embryo after fertilization and this factors are involved in the regulation of bovine embryo development.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.102-107
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• 2003

This study puts focus on the optimization of growth temperature of CIGS absorber layer which affects severely the performance of solar cells. The CIGS absorber layers were prepared by three-stage co-evaporation of metal elements in the order of In-Ga-Se. The effect of the growth temperature of 1st stage was found not to be so important, and 350$^{\circ}C$ to be the lowest optimum temperature. In the case of growth temperature at 2nd/3rd stage, the optimum temperature was revealed to be 550$^{\circ}C$. The XRD results of CIGS films showed a strong (112) preferred orientation and the Raman spectra of CIGS films showed only the Al mode peak at 173cm$\^$-1/. Scanning electron microscopy results revealed very small grains at 2nd/3rd stage growth temperature of 480$^{\circ}C$. At higher temperatures, the grain size increased together with a reduction in the number of the voids. The optimization of experimental parameters above mentioned, through the repeated fabrication and characterization of unit layers and devices, led to the highest conversion efficiency of 15.4% from CIGS-based thin film solar cell with a structure of Al/ZnO/CdS/CIGS/Mo/glass.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.393-397
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• 2007

A Haematococcus pluvialis strain isolated from the ruins of Ephesus in Turkey was investigated as regards its adaptation to laboratory conditions and maximum growth rate. In the first stage of the experiment, the growth of H. pluvialis was compared in common culture media. Furthermore, in an effort to minimize the culture costs, the second stage of the experiment compared the growth rate in the culture medium selected in the first stage with that in commercial plant fertilizers. The results demonstrated that the maximum cell concentration of 0.90 g/l, corresponding to a growth rate of $0.150d^{-1}$, was found with an N-P-K 20:20:20 fertilizer under a light intensity of $75{\mu}mol$ photons $m^{-2}s{-1}$ on the $12^{th}$ day of cultivation.