• KSBB Journal
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• v.11 no.5
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• pp.511-517
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• 1996

An amphiphilic phase enzyme reaction was used to synthesize alkyl glucosides from glucose and alkyl alcohol with immobilized ${\beta}$-glucosidase using four glycol ether cosolvents(monoglyme, diglyme, 2-methoxyethanol, and 1,4-dioxane). Monoglyme was shown to be the best cosolvent for the amphiphilic phase medium composed of water/cosolvent/alkyl alcohol admixture. To obtain high yield of alkyl glucoside by amphiphilic phase enzyme reaction, hydrophilicity-hydrophobicity of amphiphilic media and enzyme microenvironment was optimized from the viewpoints of substrate solubility, enzyme activity, water activity, and dynamic equilibrium between glucose alcoholysis and glucoside hydrolysis. Under optimum reaction conditions, the highest concentrations of hexyl, octyl, decyl, and dodecyl glucosides were 18.2, 9.68, 7.27, and 6.03g/L, respectively.

• KSBB Journal
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• v.8 no.4
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• pp.320-327
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• 1993

Latex microspheres of styrene/acryl copolymer with acrylamide functional group were used for the stable covalent immobilization of an enzyme applicable for enzymatic synthesis of glycoside. The latex microspheres were coated with polyethyleneimine to establish structural and functional properties relevant to the covalent Immobilization with a high retention of activity. Polythyleneimine-coated microspheres satisfactorily immobilized the invertase for methyl fructoside synthesis, and model reaction were formed into alginate-enclosed microspheres biocatalyst. Using the alginate-enclosed microspheres biocatalyst, the yield of model glycoside was obtained as high as 52.2% at concentration of aqueous 30%(v/v) methanol and 0.291mo1/1 sucrose solution with 2U/ml of activity. The present study showed that the latex microspheres were successfully applied to enzymatic synthesis of glycoside.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.129-136
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• 2011

Simulated Moving Bed(SMB) process consists of multiple chromatographic columns, which are usually partitioned into four zones. Such a process characteristic allows a continuous binary separations those are impracticable in conventional batch chromatographic processes. Compared with batch chromatography, SMB has advantages of continuity, high purity and productivity. Various researches have been reported for the integration of reaction and recovery during process operation on the purpose of economics and effectiveness. Simulated Moving Bed Reactor(SMBR) is introduced to combine SMB as a continuous separation process and reactor. Several cases of SMBR have been reported for diverse reactions with catalytic, enzymatic and chemical reaction on ion exchange resin as main streams. With an early type of fixed bed using catalyst, SMBR has been developed as SMB using fluidized enzyme, SMB with immobilized enzyme and SMB with discrete reaction region. For simple modeling and optimization of SMBR, a method considering convection only is possible. A complex method considering axial dispersion and mass transfer resistance is needed to explain the real behavior of solutes in SMBR. By combining reaction and separation, SMBR has benefits of lower installation cost by minimizing equipment use, higher purity and yield by avoiding the equilibrium restriction in case of reversible reaction.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.812-816
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• 1990

This study describes the sorbitol production with permeabilized cells of Zymomonas mobilis immobilized in Ca-alginate. Toluene treated cells lose activity of glucose-fructose oxidoreductase due to the leaking of enzyme from the cells. To prevent this leakage, the permeabilized cells were treated with 0.25% glutaraldehyde by stirring for 1 h at room temperature. A continuous process with glutaraldehyde treated cells was developed and no significant reduction in the degree of conversion occurred during 210 h operation. The productivities were estimated to be about $7.2{\sim}7.5\;g/l-h$ for sorbitol at dilution rate $0.18\;h^{-1}$.

• The Microorganisms and Industry
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• v.13 no.3
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• pp.37-38
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• 1987

1983년 부터 3년여에 걸쳐 유한양행 중앙연구소에서 우수 균주 개량및 발효법에 의한 효소생산을 확립시켜 산업화 가능 수준까지 도달하였다. 그러나 당사에서 생산시 국제가격하락및 품질경쟁을 예상할때 실제 생산에서는 실험실 수준의 2배 이상의 역가향상과 회수율 향상이 필요하였고, 실험실에서 손쉽고, 경제적인 생산방법들이 규모가 큰 공장 설비에서는 경제적이지 못했으므로 별도의 산업화 작업이 필요하였다. 이러한 일련의 scale-up 실험은 연구소의 여러 기초 실험결과를 토대로, 기존설비들에 적합하게, 대량생산이 가능하게, 작업이 안전하게, 생산성의 변동이 적게, 공정속도가 빠르게, 경제성이 높게하는 것을 목표로 진행시켰다. 이미 항생제 Rifamycin 발효생산을 통하여 축적된 기술 경험을 최대한 되살려 발효및 회수 정제의 산업적 기술개발에 응용하였다.

• Journal of Life Science
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• v.26 no.5
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• pp.603-607
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• 2016

A crude extracellular lipase from solvent-tolerant bacterium Pseudomonas sp. BCNU 106 was highly stable in the broad pH range of 4-10 and at temperature of 37℃. Crude lipase of BCNU 106 exhibited enhanced stability in 25% organic solvents such as xylene (121.85%), hexane (120.35%), octane (120.41 %), toluene (118.14%), chloroform (103.66%) and dodecane (102.94%) and showed excellent stability comparable with the commercial immobilized enzyme. In addition, the stability of BCNU 106 lipase retained above 110% of its enzyme activity in the presence of Cu²⁺, Hg²⁺, Zn²⁺ and Mn²⁺, whereas Fe²⁺ strongly inhibited its stability. The detergents including tween 80, triton X-100 and SDS were positive signals for lipase stability. Because of its stability in multiple organic solvents, cations and surfactants, the Pseudomonas sp. BCNU 106 lipase could be considered as a potential biocatalyst in the industrial chemical processes without using immobilization.

• Journal of Life Science
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• v.23 no.10
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• pp.1246-1251
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• 2013

An organic solvent-tolerant lipase of Pseudomonas sp. BCNU 154 that was isolated from wastewater in the industrial complex region had optimal activity at $37^{\circ}C$ and pH 8. This crude extracellular lipase from BCNU 154 exhibited maximum stability in toluene, retaining about 6.01 U/ml (117.53%) activity for 2 h. $Ca^{2+}$, $Mg^{2+}$, $NH_4{^+}$, and $Na^+$ ions and triton X-100 activated the enzymes, whereas $Ba^{2+}$, $Hg^{2+}$, and $Zn^{2+}$ ions inhibited their activity. Pseudomonas sp. BCNU 154 lipase revealed stable activity comparable to that of the commercial immobilized Novozym 435. Thus, this organic solvent-tolerant lipase could have potential as a whole cell biocatalyst in industrial chemical processes without the use of immobilization.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.412-415
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• 2004

본 연구는 감마선 조사를 이용한 알레르기 저감화 식품을 개발하기 위한 실용화 방법의 안전성을 검토하기 위해 실시되었다. 감마선 조사 후 가열 처리된 OVA는 전기영동상에서pepsin에 의해서 상당히 감소하는 것을 확인할 수 있었다. IgG 항체를 통해 살펴본 소화성은 intact OVA보다 증가하여 가수분해되기 쉬운 형태임을 알 수 있었다. 또한 효소처리 전의 IgE-binding ability는 현저히 감소하였고 최종 효소분해까지 일정하게 낮은 농도가 유지되어 가상 소화모델 시스템 내에서의 안전성을 확인할 수 있었다. 이상의 결과에서 감마선 및 가열 처리를 단독으로 시행하는 공정보다는 감마선과 가열을 병용하는 방법이 알레르기 저감 식품을 개발에 더욱 효과적일 것으로 사료된다.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.402-407
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• 1987

Glucose oxidase from Aspergillus niger KUF-04 was purified homogeneously by the procedure of seven steps including crystallization. The ball-like crystalline enzyme was obtained from the 23-fold purified enzyme solution. The glucose oxidase was found to be composed of two identical subunits and the molecular weight of the enzyme and its subunit were estimated to be about 210, 000 and 110, 000 by HPLC and SDS-acrylamide gel electrophoresis, respectively.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.132-137
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• 2018

Enzymatic treatments of maize flour (MF) were investigated using commercial carbohydrases (Ultraflo L and Pentopan 500 BG) to enhance the phenolic acid content and antioxidant property. The total phenolic acid content of the MF was 3.76 mg/100 g, whereas those of the Pentopan 500 BG and Ultraflo L treated MF were 6.85 and 39.55 mg/100 g, respectively. Particularly, ferulic acid content of Pentopan 500 BG-treated MF was 20.0 times higher than that of untreated MF (1.7 vs. 33.9 mg/100 g). Pentopan 500 BG appeared to be more effective than Ultraflo L in increasing the free phenolic acid content. Antioxidant activities of enzyme treated MF were significantly higher than untreated MF. In particular, the Pentopan 500 BG-treated MF (16.0 mmol TE/100 g) was approximately 1.5 times higher than untreated MF (12.6 mmol TE/100 g). Enzymatic hydrolysis of cell wall polysaccharides in MF could be used as an effective procedure for not only increasing phenolic content but also antioxidant activities.