• 한국미생물·생명공학회지
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• 제23권2호
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• pp.220-228
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• 1995

For polyhydroxyalkanoic acid (PHA) production, several microorganisms were isolated from sewage sludge. One of them, GB-77 strain, was chosen from its PHB/HV copolymer production on only fructose without cosubstrate. The isolated strain GB-77 was identified as the genus Alcaligenes. Optimal temperature and pH for cell growth were 36C and 6.8. Optimal medium composition was 10 g/l of fructose and 5 g/l of polypeptone, 1 $\times$ 10$^{-2}$M Na$^{2}$HP0$^{4}$, 1.3 $\times$ 10$^{-2}$M KH$^{2}$PO$^{4}$. To investigate the optimal condition for polyhydroxyalkanoic acid production two-stage culture technique was used; first stage for cell growth and second stage for PHA production on unbalanced growth conditions. Optimal conditions for high PHA production were C/N ratio 50, temperature 36$\circ$C and pH 6.8. To overcome fructose inhibition on cell growth, intermittent feeding fed-batch culture technique was used. Total cell concentration was 17.4 g/l with 9.1 g/l of PHA. The purified PHA was identified PHB/HV copolymer by NMR analysis.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.32-36
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• 2003

Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

• 한국임상수의학회지
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• 제13권2호
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• pp.149-152
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• 1996

This study was carried out to evaluate the efficiency of production of cloned embryos by nuclear translatation (NT) when using 4-cell to compact morula stage embryos as nuclear donor. In micromanitulation and electrofusion of blastomeres from 4-cell to morula stage embryos, the successful injection rate was higher with late stage blastomeres, on the contrary the fusion rate was lower. The in vitro developmental rate of NT embryos was not significantly different between cell-stages of donor blastomeres. Although the overall rate of production of cloned embryos with 4-cell. 8-cell, early and late morula stage embryos was 14.0, 18.0, 15.3 and 14.1%, respectively, the mean number of blastocysts produced with a donor embryo was the most (4.51) with the compact morulae. Therefore, it can be suggested that the embryos at thelate stage is more beneficial for the mulciple production of cloned embryos, If the late stage blastomeres have maintained their totipotency to produce intact offspring.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.128-134
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• 2008

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4g/l and 14.2g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.

• Fisheries and Aquatic Sciences
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• 제11권4호
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• pp.224-228
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• 2008

With the aim of increasing the $CoQ_{10}$ production in mass culture, the effect of aeration-agitation on the $CoQ_{10}$ production using Rhodobactor sphaeroides was investigated in a l-L bioreactor. The maximum $CoQ_{10}$ production was 1.69 mg/g of dry cell weight under conditions of 50 Lux, $30^{\circ}C$, 300 rpm, and 5-vvm aeration. The $CoQ_{10}$ production was improved to produce 2.91 mg/g of dry cell weight under reduced conditions of agitation speed (200 rpm) and aeration rate (0.2 vvm). When R. sphaeroides was cultivated under more reduced DO levels during the exponential phase of the cell, the $CoQ_{10}$ production yield of 3.88-mg/g dry cell weight was the maximum obtained. Therefore, poorer conditions of aeration-agitation resulted in higher production of $CoQ_{10}$, and thus DO content was a crucial factor in the production of $CoQ_{10}$. Accordingly, it was necessary to control the DO concentration in order to enhance the $CoQ_{10}$ biosynthesis within a large-scale production.

• 한국임상수의학회지
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• 제15권1호
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• pp.8-13
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• 1998

Change of IgG production of feline mononuclear cell(MNC) was evalual vitro. MNC was treated with lipopolysaccharide(LPS) before cortisol administration. tisol induced change of B cell subpopulation with surface IgG and reduced IgG prods against virus. However, before treatment o$\ulcorner$ MNC with LPS induced increasement of subpopulation with surface IgG and IgG production against virus. These results impel: diminution of IgG production by cortisol is well again by LPS treatment.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.882-889
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• 2002

Hantaan vims production, using human immortalized retina cell (PER. C6), was investigated to develop an inactivated virus vaccine. To infect Hantaan virus into PER. C6, two infection methods (medium-to-cell and cell-to-cell) were tried, and IFA results showed that the cell-to-cell infection method was very useful for producing Hantaan virus-infected PER, C6. Hantaan virus production was significantly affected by the growth rate of PER. C6 and the content of FBS in medium. Higher specific growth rate of infected PER. C6 and lower FBS content induced higher production of Hantaan virus. The inactivated human cell-culture vaccines with various EIA titers were prepared, their antibody responses were compared with those of inactivated suckling mouse brain vaccines ($Hantavax^처리불가$). and the result showed their immunogenicities were slightly higher than those of inactivated suckling mouse vaccines. Therefore, this study shows the possibility of the development of Hantaan virus vaccine from a human cell culture.

• KSBB Journal
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• 제24권2호
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• pp.177-181
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• 2009

This study was initiated to investigate the impacts of media types and other components on the callogenensis and cell mass production of Panax vietnamensis in the first step of the cell biomass procedure. Four media were checked: Murashige-Skoog (MS), White, Gamborg and Nitch-AII. All the four media were shown potential media for Panax vietnamensis callogenensis and cell mass production, in which the MS medium showed the best results: the successful callogenensis ratio and cell mass formation were 30% and 62,93 ${\pm}$ 3,63 mg (DW) respectively, the Nitch medium showed the lowest results: the successful callogenensis ratio and cell mass formation were 15% and 27,10 ${\pm}$ 2,24 mg (DW) respectively. The results showed that the MS medium is the most suitable medium for Panax vietnamensis callogenensis and cell mass production.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.398-405
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• 2002

Bifidobacteria have been previously shown to stimulate the immune functions and cytokine production in macrophages and T-lymphocytes. Accordingly, the RAW 264.7 murine macrophage cell line was used to assess the effects of Bifidobacterium on the proliferation and cytoskeleton reorganization of the cells. Cytokine production after exposure to Bifidobacterium was also monitored in both whole cells and cell-free extracts. When RAW 264.7 cells were cultured for 24 h in the presence of heat-killed Bifidobacterium bifidum BGN4, the proliferation of macrophages was slowed down in a dose-dependent manner and cell differentiation was observed by staining with the actin-specific fluorescent dye, rhodamin-conjugated phalloidin. Although EL-4 cells, a T-cell line, stimulated RAW 264.7 cells to produce TNF-${\alpha}$ and IL-6, the stimulatory activity of B. bifidum BGN4 decreased as the EL-4 cell number increased. When disrupted and fractionated BGN4 was used, the whole cell fraction was more effective than the other fractions for the TNF-${\alpha}$ production. In contrast, the cell-free extract exhibited the highest IL-6 production level among the fractions, which was evident even at a $1{\mu}g/ml$ concentration. The current results demonstrate that Bifidobacterium induced differentiation of the macrophages from the fast proliferative stage and that the cytokine production was differentially induced by the whole cells and cell-free extracts. The in vitro approaches employed herein are expected to be useful in further characterization of the effects of bifidobacteria with regards to gastrointestinal and systemic immunity.

• 한국수소및신에너지학회논문집
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• 제22권5호
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• pp.641-648
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• 2011

KEPRI (KEPCO Research Institute) designed and operated the lab-scale high temperature electrolysis (HTE) system for hydrogen production with $10{\times}10cm^2$ 5-cell stack at $750^{\circ}C$. The electrolysis cell consists of Ni-YSZ steam/hydrogen electrode, YSZ electrolyte and LSCF based perovskite as air side electrode. The active area of one cell is 92.16 $cm^2$. The hydrogen production system was operated for 2664 hours and the performance of electrolysis stack was measured by means of current variation with from 6 A to 28 A. The maximum hydrogen production rate and current efficiency was 47.33 NL/hr and 80.90% at 28 A, respectively. As the applied current increased, hydrogen production rate, current efficiency and the degradation rate of stack were increased respectively. From the result of stack performance, optimum operation current of this system was 24 A, considering current efficiencies and cell degradations.