• 한국식품영양과학회지
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• 제26권3호
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• pp.534-539
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• 1997

In order to reuse enzyme efficiently, a mthod for ionic binding of fructosyltransferase to a porous carrier bearing quaternary alkyl alkanolammonium groups was investigated. The fructosyltransferase activity of the immobilized enzyme increased with increasing amount of loaded enzyme, and maximally reached 770U/g of the carrier when loaded amount of the enzyme was 18.2 mg/g carrier. The immobilized fructosyltransferase had optimum pH and temperature of 7.5 and 45$^{\circ}C$, respectively, whereas soluble enzyme had 6.5 and 55$^{\circ}C$: the Km value for the immobilized enzyme was 27.8 mM for sucrose, which was the same as that of soluble enzyme. In a batch reactor, the enzyme produced a mixture of fructooligosaccharides, mainly F$_2$G, from sucrose with the slight loss of enzyme activity during continuous operation of 12 days at 42$^{\circ}C$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.136-138
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• 2002

In this work we describe the on-line monitoring technique for the analysis of fumaric acid in biotechnological processes. Fumarase and malate dehydrogenase(MDH) were immobilized on epoxy carrier and integrated into a FIA system. The effects of carrier buffer flow rate, pH, reaction temperature on the immobilized fumarase/MDH were investigated for the development of a fumarate-FIA system. Furthermore the effects of substrates, salts and metabolites dissolved in the sample on the activity of the immobilized enzyme were investigated.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.46-56
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• 2013

Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.171-178
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• 1991

The two-stage enzyme reactor, packed with cyclodextrin glucanotransferase (CGTase) immobilized on Amberite IRA 900, coupled with ultrafiltration membrane was investigated for continuous production of cyclodextrin (CD). 5% (w/v) of soluble starch was partially cyclized, in the 0.1 l first-stage immobilized enzyme reactor, up to CD conversion yield of 10% (w/w) at retention time of 0.56hr and 1.5 units of immobilized CGTase/1g of carrier. In the second stage main immobilized enzyme reactor capacity of 1.5 l, the maximum CD conversion yield of 39% (w/v) was achieved at retention time of 2.8hr and 0.47 unit of CGTase/1 g of carrier. Unreacted residual dextrin was fractionated with ultrafiltration membrane, and then, recycled into the second-stage main bioreactor to increase the CD conversion yield. The most suitable membrane size and the volume concentration ratio (concentrate: filterate) for recycling of unreacted residual dextrin were found to be 5K dalton and 4:6, respectively. CD conversion yield was increased about 3~4% upon co-immobilization of pulluanase along with CGTase. Spent Amberite IRA 900 can be reutilized consecutively more than 3 times for immobilization of CGTase after regeneration.

• 환경생물
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• 제27권3호
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• pp.244-251
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• 2009

두 가지 다른 기질의 담체를 이용하여 살조세균 Pseudomonas fluorescens HYK0210-SK09의 포집율과 microcosm에서 Stephanodiscus hantzschii의 살조능을 파악하였다. Active carbon polyvinyl alcohol (ACPA)담체가 cellulose sponge (CS)담체보다 SK09를 높게 포집하였다. 이를 이용한 microcosm에서 ACPA담체가 CS담체보다 S. hantzschii의 살조능이 높았으며 지속적이었다. 특히 ACPA담체에서는 낮은 전기전도도를 나타내어 S. hantzs-chii 분해에 따른 용출된 이온들을 흡수하고 있음을 판단할 수 있었다. 따라서 ACPA담체를 이용한 유해조류 제어는 지속적 제어와 함께 생태계의 교란을 최소화할 것으로 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.26-31
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• 1996

Since biosynthesis of lignin peroxidase from Phanerochaete chrysosporium was known to be sensitive to shear, it is interesting to understand the effects of the shear sensitivity for the overproduction of lignin peroxidase. In stirred-tank fermentor, the shear-sensitivity in lignin peroxidase biosynthesis was quantified by using Kolmogorov length scale. It was found that agitation at 80$\mu$m Kolmogorov length scale is advantageous for the production of lignin peroxidase from P. chrysosporium. To overcome the shear sensitivity in lignin peroxidase biosynthesis caused by the agitation,P. chrysosporium was immobilized on various solid carriers. The nylon-immobilized P. chrysosporium was chosen in the present study as a way to overcome the shear sensitivity at the ranges of above 50$\mu$m Kolmogorov length scale. The adhesion force between immobilized cell and carrier can be predicted by thermodynamic approach and used as a criteria to select an adequate carrier materials for immobilization.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.378-381
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• 2000

The optimal conditions and properties for the immobilization of marine bacterium Pseudomonas aeruginosa BYK-2 have been determined. For the high productioon of biosurfactant, Na-alginate, PVA, modified PVA were used as a carrier. The optimal emulsifying activity on immobilized Pseudomonas aeruginosa BYK-2 showed 1036Unit (about 2.2g/L biosurfactant) in Basal salt medium(B.S.M.) at $25^{\circ}C$, 100rpm. Ca-alginate was selected the optimal bead among PVA, modified PVA and Ca-alginate. The optimal cell load in alginate bead was 10 gCWW/100g carrier. As the results of incubation of immobilized 5g Ca-alginate bead (conditions; 3% alginate, bead diameter: 2.3mm, 10% cell load) in 50m1 production medium, The emulsifying activity of 1407Unit, about 3.0g/L biosurfactant was obtained from immobilized cell after cultivation of 92hr at $25^{\circ}C$, 100rpm.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.960-967
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• 2007

The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against $H_2O2$ inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and $30^{\circ}C$, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both $5^{\circ}C\;and\;25^{\circ}C$. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by $H_2O2$ and supplying additional $O_2$ to the reaction system.

• KSBB Journal
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• 제23권3호
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• pp.213-218
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• 2008

일반적으로 약주 생산 공정에서 고정화 담체를 이용하는 연속식 반응기에서는 회분식 반응기와 비교하여 생성되는 알코을 생성량 못지않게 연속식 반응기에서 연속적으로 생성되고 있음을 알 수 있었다. 고정화 담체를 이용한 연속식 반응기는 약주의 품질에 긍정적인 효과를 보이는 것으로 나타났으며 담금 공정에서의 처리효과를 분석한 결과는 다음과 같다. 1) 회분식 배양에서 에탄올의 생성량은 1차 담금 1일 째부터 12%이상 증가하는 것으로 나타났으며 연속배양은 2차 담금에 효모를 주입하지 않아도 회분식 배양에서와 같은 알코올 도수를 가지면서 지속적으로 얻어졌다. 또한 pH는 4.4에서 3.8로 감소하는 패턴을 나타냈으며 산소농도는 1 ppm정도 차이가 나타났으나 이는 연속적으로 기질이 반응기로 주입되기 때문에 증가된 것이다. 2) 폴리플로필렌에 폴리스티렌을 샌드위치식으로 접합한 고정화 미생물담체는 연속배양에서 효모 주입 없이도 회분식 배양과 비교해보았을 경우에 당화과정과 알코올 생성과정 등이 서로 상반되는 패턴을 갖으면서 생물학적인 반응이 정상적으로 진행됨을 증명하였다. 3) 연속배양의 실험결론을 토대로 1차 담금에서 당의 생성기질을 이용하였을 경우, 10톤/일 생산하는 약주생산 공장은 1년간 효모 투입비용을 환산해 본 결과 1억원 이상의 투입비용이 감소하는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.768-774
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• 2017

Horseradish peroxidase (HRP) catalyzes the oxidation of aromatic compounds by hydrogen peroxide via insoluble polymer formation, which can be precipitated from the wastewater. For HRP immobilization, poly(lactic-co-glycolic acid) (PLGA) fine carrier supports were produced by using the Nano Spray Dryer B-90. Immobilized HRP was used to remove the persistent 2,4-dichlorophenol from model wastewater. Both extracted (9-16 U/g) and purified HRP (11-25 U/g) retained their activity to a high extent after crosslinking to the PLGA particles. The immobilized enzyme activity was substantially higher in both the acidic and the alkaline pH regions compared with the free enzyme. Optimally, 98% of the 2,4-dichlorophenol could be eliminated using immobilized HRP due to catalytic removal and partly to adsorption on the carrier supports. Immobilized enzyme kinetics for 2,4-dichlorophenol elimination was studied for the first time, and it could be concluded that competitive product inhibition took place.