• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.227-229
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• 1999

Animal cell culture media are usually supplemented with fetal bovine serum (FBS); however, the use of FBS presents certain problems including high cost. By using an adaptation process and the addition of silkworm hemolymph, the FBS concentration can be reduced without causing a significant decrease in cell growth.

• KSBB Journal
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• 제32권2호
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• pp.90-95
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• 2017

Mammalian cell cultures have been used extensively to produce proteins for therapeutic agent because of their ability to perform post-translational modification including glycosylation. To produce recombinant protein, many factors and parameter are considered such as media composition, host cell type, and culture process. In this study, recombinant human erythropoietin (rhEPO) producing cell line was established by using glutamine synthetase system. To reduce serum concentration in media, we compared direct adaptation with step adaptation. Cell growth was faster in step adaptation. In low-level serum media, there were insufficient glucose for cell growth. Thus, we added glucose in low-level serum media from 2 g/L to 4.5 g/L. Titer of rhEPO was higher than other conditions at 4.5 g/L of glucose. Additionally, N-methyl-D-aspartate (NMDA), 13-cis-retinal, and pluronic F-68 (PF-68) were added to enhance productivity in CHO cell cultures. In conclusion, we applied CHO cell producing rhEPO to low-level of serum in media using step-adaptation. Also, we confirmed positive effect of NMDA, 13-cis-retinal, and PF-68.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.564-570
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• 2005

In the present study, the protective effects of Bcl-2 over-expression in a suspension culture (without any adaptation) and spent medium (low nutrient and high toxic metabolite conditions) were investigated. In the suspension culture without prior adaptation, the viability of the control cell line fall to 0% by day 7, whereas the Bcl-2 cell line had a viability of 65%. The difference in the viability and viable cell density between the Bcl-2 and control cell lines was more apparent in the suspension culture than the static culture, and became even more apparent on day 6. Fluorescence microscopic counting revealed that the major mechanism of cell death in the control cell line in both the static and suspension cultures was apoptosis. For the Bcl-2 cell lines, necrosis was the major mode of cell death in the static culture, but apoptosis became equally important in the suspension culture. When the NS0 6A1 cell line was cultured in spent medium taken from a 14 day batch culture, the control cell line almost completely lost its viability by day 5, whereas, the Bcl-2 still had a viability of 73%. The viable cell density and viability of the Bcl-2 cell line cultivated in fresh medium were 2.2 and 2.7 fold higher, respectively, than those of the control cultures. However, the viable cell density and viability of the Bcl-2 cultivated in the spent medium were 8.7 and 7.8 fold higher, respectively, than those of the control cultures. Most of the dead cells in the control cell line were apoptotic; whereas, the major cell death mechanisms in the Bcl-2 cell line were necrotic.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.171-173
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• 2003

본 연구에서는 생분해성 고분자 나노입자를 이용하여 부착성 세포의 세포군집 (cell aggregates) 형성을 촉진시켜 무혈청 배지에서 3차원적 부유 배양하는 방법을 개발했다. 생분해성 고분자 나노입자의 사용은 무혈청 배지 부유배양에서 부착성 동물세포인 HEK 293 세포의 세포군집 형성과 세포증식(나노입자를 사용하지 않은 대조군과 비교하여 2배 이상)을 촉진하였다. 일반적으로 무혈청배지 부유배양에 세포를 적응(adaptation)시키는 데에는 시간이 오래 걸리고 많은 비용이 드는데, 이 연구에서 개발된 방법은 이러한 세포적응 공정이 필요없다. 이 배양법은 여러 부착성 동물세포의 산업적 대량배양에 유용하게 사용될 수 있을 것이다.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.87-90
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• 1995

A process of organically bound germanium preparation was developed for healthy food using inorganic germanium adapted Saccharomyces cerevisiae. Adaptations of Saccharomyces cerevisiae against inorganic germanium were successively carried out through stepwise increase of GeO$_{2}$ concentration in order to produce high quantities of germanium bound yeast. Productivity of yeast and quantities of germanium in yeast were obtained 70.2 g/l and 9780 ppm, repectively, when adapted yeast and fed batch culture were used. Germanium taken-up yeast is to be organically bound germanium by evidence of no difference of germanium content after dialysis.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.409-412
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• 2000

In hybridoma cell culture, $NH_4\;^+$ is the most important toxic byproduct so far identified. It has been postulated that $NH_4\;^+$, which is similar to $K^+$ in size, is taken up non-specifically by the cells through a potassium transport system, and that the addition of $K^+$ to the culture medium may have a detoxifying effect of $NH_4\;^+$. Thus, in this study the effects of varying $Na^+/K^+$ ratios by adding potassium were investigated for hybridoma physiology and CHO cell morphology respectively. The possible use of potassium addition for the adaptation of CHO cells to suspension culture is discussed.

• KSBB Journal
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• 제13권3호
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• pp.231-237
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• 1998

세계보건기구 (WHO)가 백신 생산에 권장하고 있는 표준세포 주인 Vero 세포에 약독화 일본뇌염바이러스인 SA14-14-2 ( (PDK)를 연속 계대배양을 통해 적응(adaptation)시켜, tIter가 $10^7$pfu/mL을 넘는 SA-14-14-2(Vero)을 분리하였다 바이러스 배양 최적온도는 $35^{\circ}C$이며, T -flask에서 배양된 바이러스의 최고 tIter는 감염 후 4일째에 $4\times10^7$ pfu/mL로 관찰되었다. 또한 무혈청배지에서도 바이러스 증식이 활발하여 2% 혈청이 보충된 정우와 거의 비슷한 바이라스 tIter를 보였다. 바이러스 대량 배양을 위해 roller bottle culture와 미 립 담체 플 이용한 spinner flask culture 가능성에 대하여 고찰하였다 바이러스 감염을 위한 미립담체에서의 Vera cell monolayer는 초기 세포 농도 $4\times10$ cells/mL로 접종하여 50 rpm에서 7일간 배양하여 얻을 수 있었다. 바이러스의 roller bottle 배양이 spinner flask 배양보다 바이러스 tIter변에서 2배 내지 3배 높 았고, $10^7$pfu/mL을 넘는 배양 기간도 하루 죄었다. 하지만 두 배양 방법 모두 T -flask 배양에서와 같이 무혈청 배지를 사용 하여도 바이라스 증식이 활발했고, 최고조의 tIter를 보이는 배 양기간은 감염 후 2일째로써 T -flask 배양에서 보다 2일 빨랐다. Roller bottle culture의 경우, 감염 후 3일부터 17일까지 2 일 간격으로 배양액을 무혈청 EMEM으로 100% 교체하면서 매 양을 지속한 결과 3일부터 9일까지 $10^7$pfu/mL을 념는 tIter가 유지되는 것이 확인되어 바이러스의 multi-harvest가 가능한 것 로 고찰되었다. 상기의 결과는 생산성 면에서 매우 유리한 결 과로 제품의 생산 단가플 낮추고 작업 노력을 절감하는 기대 효 과가 클 것으로 예측된다.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.243-251
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• 2011

The gene bolA was discovered in the 80's, but unraveling its function in the cell has proven to be a complex task. The BolA protein has pleiotropic effects over cell physiology, altering growth and morphology, inducing biofilm formation, and regulating the balance of several membrane proteins. Recently, BolA was shown to be a transcription factor by repressing the expression of the mreB gene. The present report shows that BolA is a transcriptional regulator of the dacA and dacC genes, thus regulating both DD-carboxypeptidases PBP5 and PBP6 and thereby demonstrating the versatility of BolA as a cellular regulator. In this work, we also demonstrate that reduction of cell growth and survival can be connected to the overexpression of the bolA gene in different E. coli backgrounds, particularly in the exponential growth phase. The most interesting finding is that overproduction of BolA affects bacterial growth differently depending on whether the cells were inoculated directly from a plate culture or from an overnight batch culture. This strengthens the idea that BolA can be engaged in the coordination of genes that adapt the cell physiology in order to enhance cell adaptation and survival under stress conditions.

• Journal of Microbiology and Biotechnology
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• 제17권3호
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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.

• KSBB Journal
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• 제7권4호
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• pp.308-316
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• 1992

유전자 재조합 균주의 성질이 불안정할 경우,2 단 연속 배양조를 사용하면 여러가지 이점이 있다. 본 논문은 2단 연속 배양조의 최적화를 목적으로 유전자 재조합 대장균의 과도상태 거동을 1단 및 2단 연속 배양조에서 연구한 결과를 다룬다. 희석율이 갑자기 변할 때 대장균은 새로운 희석율에 적응하기 위해 성장속도를 바꾸는데 적응 속도가 성장 잠재력에 비례한다는 가정아래 수학적 이론식을 도출하였으며, 이때 중요한 동력학적 변수는 무차원의 순간속도 증가(a) 빛 적응속도 상수(k)이었다. 이 상수들을 여러 온도와 희석 속도에서 실험적으로 측정하였고, 이 측정값을 모렐식에 적용한 결과 실제 2단 배양조의 미생물 성장속도의 과도기적인 성질을 잘 묘사하는 것으로 나타났다.