• Journal of Life Science
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• v.17 no.2 s.82
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• pp.293-297
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• 2007

Green fluorescent protein (GFP) is an attractive reporter for bioprocess monitoring. A fluorescence-based method was developed to quantify GFP levels in transgenic plants and protein extracts. In this study, GFP was produced and secreted from suspension cells derived from transgenic rice. The RAmy3E promoter placed before the GFP gene controlled by sugars such as sucrose. The effects of sucrose concentration on the secretion of GFP and total protein into the medium were investigated in batch suspension culture. It was possible, therefore, to induce the expression of the GFP by removing sucrose from the cultured media or by allowing the rice suspension cells to deplete sucrose catabolically. The dry cell weight (7.06 g/L) and GFP level were detected as highest at 12%, 3% sucrose after 20 day culture, respectively. However secreted GFP fluorescence at the other sucrose concentrations (6%, 12%, 18% and 24%) were a little amount in media.

• KSBB Journal
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• v.16 no.4
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• pp.376-380
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• 2001

The human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was produced from cell suspension culture of transgenic tobacco which was transformed by using Agrobacterium harboring the hGM-CSF gene. To improve the production of hGM-CSF in batch culture system, the effects of initial sucrose concentration and inoculum size were investigated. The results show that the hGM-CSF production was not affected by small inoculum size in medium containing either low or high concentration of sucrose. However, the production of hGM-CSF was increased under increasing of the inoculum sizes and sucrose concentration. Under the combination of inoculum and sucrose concentration, the maximum hGM-CSF production of 720 $\mu$g/L was obtained at 90 g/L of initial sucrose concentration and 110 g/L of inoculum size.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.171-178
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• 2004

Glucose alone was found to be the most effective carbon source for producing compactin. An initial glucose concentration of 40 g/L gave the highest compactin concentration of 250mg/L. Among the various nitrogen sources, when 5g/L of pharmamedia and soybean meal as the sole nitrogen source were used, respectively, the compactin concentration was higher than 250mg/L. Especially, in the case of the mixture of 6 g/L of pharmamedia and 8 g/L of soybean meal, the compactin concentration was 400mg/L. To select the best surfactant for effective compactin production, various surfactants were investigated. When Triton X-100 was used, the maximum compactin concentration was 445mg/L. With the initial concentration ranging from 1.5 to 2.0 g/L, the compactin concentration was the highest at 465-450mg/L. The cell concentration was similar to that of the control without the addition of Triton X-100. On the other hand, when the above 4.0 g/L of Triton X-100 were used, the cell concentration decreased. Using the based results, the continuous fed-batch cultures by adding the Triton X-100 were carried out for 10 days in an air-lift bioreactor. When 1.5 g/L of Triton X-100 was added to the culture broth at 0, 4, and 8 days of culture, respectively, the compactin production was increased with the increase of culture time. The maximum compactin concentration after 10days of culture was 1,200mg/L, which was about 2.0-fold higher than that of the control without the addition of Triton X-100.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.104-109
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• 2001

The yield of infective juveniles of Heterorhabditis bacteriophora (Tf strain) in vitro monoxenic liquid culture was improved significantly as the amount of symbiont biomass, Photorhabdus sp. strain Tf, increased. To investigate the influence of abiotic factors on the growth and biomass production of Photorhabdus sp. strain Tf, triplicate flask cu1tmes were performed. The optinal temperature and medium pH for the growth of Photorhahdus sp. strain Tf were 30$^{\circ}$C and between pH 5.5-7.3, respectively. Aeration also improved greatly growth and yield of biomass of Photorhabdus sp. strain Tf. Photorhabdus sp. strain Tf in batch fermentation showed growth-associated pattem in terms of pigment production, and the pH of culture medium rose steadily until growth stopped dUling the fermentation. Both pigment production and culture pH rise would be useful parameters indicating a reliable growth of Photorhabdus sp. strain Tf.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.343-347
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• 2019

This study was performed to develop an economical culture method of lactic acid bacteria (LAB) for kimchi fermentation. Leuconostoc mesenteroides WiKim32 was grown to $1{\times}10^9CFU/mL$ and maintained at 8.88 log CFU/mL for four days by culturing in kimchi cabbage juice (KCJ) without supplements and sterilization. Leuconostoc mesenteroides WiKim32 was cultured in 100 mL of KCJ by inoculating with 0.1% starter culture and adding 100 mL of KCJ everyday by adjusting pH to 5.5 using 1 M NaOH at $20^{\circ}C$ for four days. KCJ was prepared by extraction of kimchi cabbage leaves after washing them with citric acid and ethanol. Adjusting pH over 6.0 was favorable for the growth of LAB in the initial stage, but LAB growth was retarded in the later stage. In contrast, adjusting pH below 5.0 was not beneficial for the growth of LAB; therefore, pH was adjusted to 5.5.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.426-429
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• 2001

The continuous production of L -proline was studied using L-histidine auxotrophic mutant of Corynebacterium acetoacidophilum under various substrate limited conditions. Among the $NH_4\;^+$ $PO_4\;^3$ and L -histidine limited conditions, the highest production of L -proline was observed under the L-histidine limited condition. Under $NH_4\;^+$ and $PO_4\;^3$ limited conditions, no or poor L-proline production was observed, respectively. For the kinetic parameters under L -histidine limitation the specific rate of L -proline production was increased with dilution rate upto $0.1hr^{-1}$ but decreased above $0.1hr^{-1}$. The volumetric rate of L -proline production was showed similar pattern with specific rate. The dried cell weight was gradually increased according to decrease the dilution rate. Specific rate of glucose consumption was proportionally increased with dilution rate. The results of continuous culture (higher production of L-proline at dilution rate $0.1hr^{-1}$) will be used in fed-batch culture for the control of cell growth rate and mass production of L-proline.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.666-670
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• 2001

Levofloxacin is L-form stereoisomer of ofloxacin. It has better antibacterial activity than D-oflxacin. In this study, levofloxacin was produced enantioselectively by using high density culture of recombinant E. coli containing a foreign esterase gene. Final cell concentration was 89 g/L at the end of fed-batch culture and the cells were used for levofloxacin production after IPTG induction at the optimized condition. For the immobilization of recombinant E. coli. 1.5% sodium alginate showed the best result to maintain enzyme activity and enantioselectivity.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.440-444
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• 2003

A new approach for ground water treatment combines a permeable Fe(0) barrier to breakdown higher chlorinated solvents like PCE and TCE with a down gradient aerobic biological treatment system to biotransform less chlorinated solvents, such as DCE and vinyl chloride (VC). The expected bacterial performance down gradient of an Fe(0) barrier was evaluated through laboratory batch experiments with a toluene-degrading mixed culture that cometabolically transforms cis-1,2-DCE and VC. The amount of cis-1,2-DCE (initially at 2,000 ppb) and VC (initially at 2,000 ppb) transformed was controlled by the initial toluene(20,000 ppb) concentration. VC was removed much more effectively than Cis-1,2-DCE, and a higher toluene concentration in comparison to the co-substrate concentrations was needed for complete co-substrate removal. Overall, the coupling of an Fe(0) barrier and subsequent biodegradation appears feasible for remediation of complex mixtures of chlorinated solvents and petroleum hydrocarbons in groundwater.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.18-22
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• 1997

The conditions for production of high cell density of Bifidobacterium longum were investigated and the cross-flow filtration system was used to remove the inhibitory metabolites, lactic acid and acetic acid. The maximum cell growth was observed with glucose as carbon source at the concentration of 50 g/l at $37^{\circ}C$ with the initial pH 6.5. When B. longum was cultured in a cross-flow filtration system, the maximum cell growth was observed at a dilution rate(D) of $0.31\;h^{-1}$ and the dry cell weight was 16.4 g/l($3.5{\times}10^{10}\;cell/ml$), which was about four times higher than that obtained in the batch culture with pH control.

• KSBB Journal
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• v.4 no.1
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• pp.31-33
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• 1989

The effect of growth rate change on glucose consumption and Ammonia production rate in batch culture of hybridoma was studied. The methods regulating growth rate of hybridoma were 1) decrease of serum concentration, 2) decrease of culture temperature and 3) addition of growth inhibitor (thymidine). The experimental results showed that hybridoma growth rate was dropped by 20~50%, while glucose consumption and ammonia production rate was decreased up to 40% On the other hand, the final concentration of monoclonal antibody was shown to be increased as high as 100% when the concentration of serum was decreased from 2% to 0.2%.