• 한국식품영양학회지
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• 제11권3호
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• pp.319-322
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• 1998

본 실험에서는 GI 활성이 높은 alkalophilic Streptomyces sp.를 사용하여 2% $ extsc{k}$-carrageenan에 균체를 고정화 균체의 효소학적 특성을 살펴보았다. pH stability는 pH가 7.5~8.5에서 GI 활성이 가장 높았으며, reaction temperature는 7$0^{\circ}C$, Co2+는 10-3M, Mg2+는 10-3M일 때 GI 활성이 가장 높은 것으로 나타났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.536-539
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• 2000

A simple and effective method has been developed for the immobilization of the cell on polyurethane foam. Two types of commercially available polyurethane foam and Hydro-filt were tested. The ultimate purpose of the process is to produce low-cost materials for hydrogen sulfide removal which are being increasingly used for industrial application. Effect of several parameters were studied on the cell loading. These parameters were type, size, and amount of polyurethane foam. MC-70 was the best immobilization material of three type of carriers, and optical particle size was $5{\sim}8mm$ and amount of polyurethane foam was 8g/L.

• 한국식품영양과학회지
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• 제23권2호
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• pp.322-327
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• 1994

L-라이신 생산성의 향상을 목적으로 생체반응기를 이용한 연속발효시스템의 개발을 시도하였다. 먼저, Corynebacterium glutamicum ATCC 21514균체의 고정화조건에 대하여 검토하였는데 균체를 4% k-carrageenan에 포괄하였을 때 76.2%의 고정화율을 나타내었고, 겔강도는 4.0kg이었다. 이 고정화균체를 사용하여 생체반응기를 제작하여 L-라이신의 연속생산에 응용하였으며, 최적조건하에서 얻은 결과를 회분식의 결과와 비교하였다. 14일간의 연속발표에서 얻는 실험결과 공급당의 L-라이신으로의 전환율은 36.7%이었고, L-라이신의 생산성은 4.96mg/ml/mg-dry cell weight/hr로서 생균체나 고정화균체에 의한 회분식발효의 경우에 비하여 각각 2.5배와 4.1배 높았다.

• KSBB Journal
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• 제21권5호
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• pp.384-388
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• 2006

본 연구에서는 고정화 방선균을 이용한 이차대사산물생산 공정 개발에 있어서 고려해야 할 중요한 사항인, 고정화세포의 반복사용 가능성을 조사하였다. 또한 축축한 담체에 균사체 형태의 생산균주의 고정화가능성에 대하여 알아보았다. 셀라이트 담체에 고정화된 고생산성 Streptomyces lincolnensis 돌연변이주를 이용한 반복회분식 배양에서, 회분수가 증가함에 따라 고정화세포의 린코마이신 생산성이 증가하였고 9번째 회분에서는 1007 $({\pm}256)$ mg/L의 린코마이신이 얻어졌다. 10번의 반복회분동안 고정화세포에 의해 얻어진 린코마이신 총양을 기준으로 계산된 고정화세포 배양의 생산성은 현탁회분식 배양에 비해 1.4배 높았다. 축축한 담체와 배지가 포함된 플라스크에 균사체 형태의 생산균주를 접종하고 배양 후 생성된 고정화세포 농도와 린코마이신 양은 건조한 담체에 포자상태의 생산균주를 고정화한 후 배양하여 얻어진 것에 비하여 다소 높음이 관찰되었다. 이는 균사체 형태의 생산균주가 축축한 담체에 쉽게 고정화되는 것을 의미한다. 실제 생산규모를 고려할 때, 본 연구팀에서 개발한 방선균 고정화방법은 담체 멸균 및 세포고정화 단계에서 추가적인 설비가 필요 없으며, 이는 고정화단계에서 숙련된 기술과 추가의 설비를 요하는 다른 방법들에 비하여 실용적이며 경쟁력 있는 생물 공정이라고 사료된다.

• Journal of Trauma and Injury
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• 제19권2호
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• pp.105-112
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• 2006

Purpose: Many stresses produce reactive oxygen species and bring about mechanism of antioxidant reaction. Cytokine and a neurotransmitter through the cell membrane, as well as signal transduction through the cell membrane, are used for various pathological condition of the brain, such as neurodegenerative disease. There are several antioxidant enzymes in cells (superoxcide dismutase, glutathion peroxidasae, peroxiredoxin catalase, etc.) Methods: This study used single- or double-label immunohistochemical techniques to analyze mouse spinal neuron cells expressing Prx I and Prx III after acute mobilization stress. Results: Prx I was observed in dendritic cell of the gray matter of the spinal cord, and Prx III was observed in the cytoplasm of the GM of the spinal cord. Conclusion: The results of this study will help to explain differences of expression in the distributions of the peroxiredoxin enzymes of the spinal cord.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1234-1241
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• 2016

Methanol is a versatile compound that can be biologically synthesized from methane (CH₄) by methanotrophs using a low energy-consuming and environment-friendly process. Methylocella tundrae is a type II methanotroph that can utilize CH₄ as a carbon and energy source. Methanol is produced in the first step of the metabolic pathway of methanotrophs and is further oxidized into formaldehyde. Several parameters must be optimized to achieve high methanol production. In this study, we optimized the production conditions and process parameters for methanol production. The optimum incubation time, substrate, pH, agitation rate, temperature, phosphate buffer and sodium formate concentration, and cell concentration were determined to be 24 h, 50% CH₄, pH 7, 150 rpm, 30℃, 100 mM and 50 mM, and 18 mg/ml, respectively. The optimization of these parameters significantly improved methanol production from 0.66 to 5.18 mM. The use of alginate-encapsulated cells resulted in enhanced methanol production stability and reusability of cells after five cycles of reuse under batch culture conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.257-260
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• 2002

Dissolved oxygen level of cell culture media has a critical effect on cellular metabolism, which governs specific productivity of recombinant proteins and mammalian cell growth However, in the cores of cell aggregates or cell-immobilized beads, oxygen level frequently goes below a critical level. Mammalian cells have a number of genes induced in the lower level of oxygen, and the genes contain a common cis-acting element (-RCGTG-), hypoxia response element (HRE). By binding of hypoxia inducible factor-l (HIF-I) to the HRE, promoters of hypoxia inducible genes are activated, which is a survival mechanism. In this work, to develop a CHO cell capable of producing recombinant proteins in immobilization and high density cell culture efficiently, mammalian expression vectors containing human tissue-type plasminogen activator (t-PA) gene controlled by HRE were constructed and stably transfected into the CHO cells. In $Ba^{2+}$ -alginate immobilization culture, CHO/pCl/dhfr/2HRE-t-PA cells produced 2 folds higher recombinant t-PA activity than CHO/pCl/dhfrlt-PA cells without $CoCl_2$ treatment. Furthermore, in repeated fed batch culture, productivity of t-PA in immobilized CHO/pCI/dhfr/2HRE-t-PA cells was 121 ng/ml/day, total production of 0.968 mg/day at 11 days culture while CHO/pCIIdhfrlt-PA cells was 22.8 ng/ml/day. All these results indicate that HRE is very useful for the enhancement of protein productivity in mammalian cell cultures.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.77-81
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• 1997

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. To prevent washout and to develop an efficient bioreactor, immobilization of sutibal microorganisms could be sensible approach. Strains and permeabilized cell encapsulated in cellulose nitrate microcapsules and immobilized on polystyrene films were prepared by the method described in the previous study. In the wastewater treatment system, nitrification of ammonia component is generally known as rate controlling step. To enhance the rate of nitrification, firstly nitrifying strains Nitrosomonas europaea(IFO14298), are permeabilized chemically, and immobilized on polystyrene films and secondly oxidation rates of strain system and permeabilized strain system are compared in the same condition. with 30 minute permeabilized cells, it took about 25 hours to oxidize 70% of ammonia in the solution, while it took about 40 hours to treat same amount of ammonia with untreated cells. All the immobilization procedures did not harm to the enzyme activity and no mass transfer resistance through the capsule well was shown. In the durability test of immobilized system, the system showed considerable activity for the repeated operation for 90 days. With these results, the system developed in this study showed the possibility to be used in the actual waste water treatment system.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.141-146
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• 1997

A new sensing system based on the immobilization of luminescent batcteria, Photobacterium phosphoreum, was proposed for continuous real-time monitoring of polluants. The response curves demonstrate that Photobacterium phosphoreum immobilized on the strontium alginate was very sensitive to seven reference chemicals used. The significant inhibitory concentrations for bioluminescence emission were 5 ppm for Pb(NO3)2, NiCl2, CdCl2, 50 ppm for NaAsO2, 0.1ppm for HgCl2, 0.5ppm for pentachlorophenol and less than 5ppm for SDS, respectively. The alginate mixed-cells (AMC) retained their luminescence during experimental period (29 days) under storage condition of -8$0^{\circ}C$. The variables affecting performance of continuous flow through monitoring (CFTM) were optimized in order to ensure stability and efficiency. The flow through cell with strontium-alginate immobilized luminescent bacteria was tested with salicylate and 4-nitrophenol and a rapid response of luminescence was recorded by time drive mode in bioluminescence spectrometer after exposure to both toxicants.

• Korean Chemical Engineering Research
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• 제54권5호
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• pp.693-697
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• 2016

본 연구에서는 탄소나노튜브(CNT), 글루코스 산화효소(Glucose oxidase, GOx) 및 다양한 분자량의 가지달린 폴리에틸렌이민(Polyethyleneimine, branched, bPEI)을 물리적으로 결합하여 GOx/PEI/CNT 구조를 제조한 뒤, 가교제인 테레프타랄데하이드(Terephthalaldehyde, TPA)와 알돌축합반응을 통해 TPA/[GOx/bPEI/CNT] 구조의 촉매를 합성하였으며, 각각의 전기화학적 특성 및 장기안정성 등을 평가하였다. GOx/PEI/CNT의 경우, PEI의 분자량의 증가에 따라 유의한 차이를 확인할 수 없었으나, TPA 도입한 TPA/[GOx/bPEI/CNT]는 PEI 분자의 증가에 따라 전자전달 및 장기안정성은 향상되며 글루코스의 물질전달은 감소함을 확인하였다. 또한 효소연료전지 음극 촉매로서의 최적 bPEI 분자량을 확인한 결과, 750 k PEI를 이용한 촉매(TPA/[GOx/bPEI-750k/CNT]에서 최고의 최대전력밀도($0.995mW{\cdot}cm^{-2}$)를 얻을 수 있음을 확인하였다.