• Journal of Microbiology and Biotechnology
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• 제24권1호
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• pp.80-86
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• 2014

Tannase (Tan410) from a soil metagenomic library was immobilized on different supports, including mesoporous silica SBA-15, chitosan, calcium alginate, and amberlite IRC 50. Entrapment in calcium alginate beads was comparatively found to be the best method and was further characterized. The optimum pH of the immobilized Tan410 was shifted toward neutrality compared with the free enzyme (from pH 6.4 to pH 7.0). The optimum temperature was determined to be $45^{\circ}C$ for the immobilized enzyme and $30^{\circ}C$ for the free enzyme, respectively. The immobilized enzyme had no loss of activity after 10 cycles, and retained more than 90% of its original activity after storage for 30 days. After immobilization, the enzyme activity was only slightly affected by $Hg^{2+}$, which completely inhibited the activity of the free enzyme. The immobilized tannase was used to remove 80% of tannins from a green tea infusion on the first treatment. The beads were used for six successive runs resulting in overall hydrolysis of 56% of the tannins.

• 한국식품영양학회지
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• 제2권2호
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• pp.14-20
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• 1989

A strain of Saccharomyces cerevisiae BY-366 was isolated to produce a strong sucrose-hydrolyzing enzyme. After entrapment of yeast cell invertase with alginate, enzymatic properties of immobilized cells were investigated. The results are as follows. 1. The optimum pH of invertase in immobilized cells and non- immobilized cells was 6.0 and 5.0, and pH stability of invertase in immobilized cells and non- immobilized cells was 6.0 and 5.0, respectively. 2 Activation energy of immobilized cells was 4.7 kcal/mol. 3 The immobilized preparation exhibited high resistance to heat and urea Induced denaturation. 4, The bead size less than 2 mm in diameter was desirable. 5. In spite of repeated use, the enzyme activity of immobilized cells was inhibited slightly in batch reaction, and a small column of the immobilized preparation could hydrolyze relatively high concentration of sucrose almost quantitatively to more than 6 days.

• 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$^{\circ}C$.

• 한국미생물·생명공학회지
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• 제13권2호
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• pp.115-118
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• 1985

리파마이신 B 산화효소의 활성을 갖고 있는 Humicola spp. (ATCC 20620)를 아세톤 처리 한 후 cellulose acetate로 고정화하여 그 특성을 조사하였다. 고정화 효소에 있어서 pH는 7.2온도는 50-55%에서 최대 활성을 보였으며, 비고정화 효소에 비하여 pH와 온도변화에 덜 민감하였다. 외경 3mm bead size에서 20%의 활성회수율을 보였으며, storage stability는 4$0^{\circ}C$ 이하에서는 아주 좋았으며 5$0^{\circ}C$ 이상에서는 급격히 활성이 감소하였다. 고정화 담체로서 cellulose acetate는 물리적으로 견고하여 삼상반응기의 packing material로써 적당하였다.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.257-263
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• 2012

바이오디젤은 화석연료인 경유의 대체에너지로써 비독성이고 재생 가능한 에너지이다. 바이오디젤생산방법은 크게 산 염기 초임계 효소방법으로 분류되는데 본 연구에서 친환경적으로 바이오디젤을 생산할 수 있는 초임계공정과 효소고정화공정에 대해 연구하였다. 연간 10,000톤의 바이오디젤을 생산하는 공정을 대상으로 PRO II 공정모사기를 통해 전환률과 에너지소비량을 알아보기 위한 공정모사를 실시하였다. 그 결과 초임계공정에서의 전환률은 91.17%(0.9% 글리세롤 포함), 효소고정화공정에서는 93.58%(1.0% 글리세롤 포함)로 나타났다. 이 결과는 효소고정화공정이 높은 전환률을 보였지만 바이오디젤의 순도는 초임계공정에서 높게 나타났음을 보여준다. 한편, 에너지소비량 측면에서 초임계공정과 효소고정화공정이 각각 8.9, 3.9MW를 나타났다. 즉, 초임계 공정이 효소고정화공정에 비하여 2.3배 많은 에너지를 소모한다는 것을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.766-772
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• 2002

The plasmid, pJHKJ4, containing the endoxylanase gene, was introduced into Bacillus subtilis DB 104. The recombinant cells produced 587 unit/ml of endoxylanase at 33 h. The endoxylanase was immobilized covalently on the surface of silica fur effective xylan hydrolysis. The activities of the immobilized and free endoxylanases were optimal at pH 6.5 and 10 mM $MnSO_4$. The optimal temperature of the immobilized endoxylanase was $60^{\circ}C$, whereas that of the free endoxylanase was $65^{\circ}C$. Under these optimal conditions, the activity of the immobilized endoxylanase was 1.7 times higher than that of the fee endoxylanase. From microscope photographs, the immobilized endoxylanase was found to be bounded and evenly distributed on the surface of silica, a nonporous solid support. The enzyme kinetics between the immobilized and free endoxylanases was estimated to be uncompetitive, when plotting double-reciprocal plots against xylan concentrations and endoxylanase activities. These results suggest that the higher activity of the immobilized endoxylanase may be due to increased formation of enzyme-substrate complex, because of the easy accessibility of the immobilized enzyme to the polysaccharide-xylan as a high molecular weight substrate.

• 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.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.297-301
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• 2004

The dTDP-D-glucose 4,6-dehydratase from Salmonella enterica was immobilized using covalent binding to cyanogen bromide activated sepharose. The immobilized enzyme was used to produce dTDP-4-keto-6-deoxy-D-glucose, a key sugar intermediate that can be used economically to produce diverse classes of unusual sugars appended in various antibiotics. The enzyme was immobilized on the sepharose after activation with cyanogen bromide. The maximum immobilization (80.03％) was achieved after 14 h of coupling. The covalently immobilized enzyme was stable, and an average of 78.4 ％ conversion was achieved until 120 h of immobilization when it was repeatedly used. Similar conversion was noticed for the first batch using the enzyme entrapped-hydrogel but activity was gradually decreased in the following batches. The production of dTDP-4-keto-6-deoxy-D-glucose by using an immobilized enzyme has high potential for commercial application.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.157-163
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• 2017

Immobilized enzymes have become the subject of considerable interest due to their excellent functional properties such as reusability, cost-effectiveness, and optimality during the past decades. Enzyme immobilization technology is not only used in industrial processes, but also a component technology of products for medical diagnostics, therapy, food industry, bio energy, and biomaterial detection. In this review, new methods for enzyme immobilization are introduced, and the advantages and disadvantages of a variety of techniques in enzyme immobilization will be also discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.57-66
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• 2002

This review focuses on the use of immobilized lipase technology for the hydrolysis of oils. The importance of lipase catalyzed fat splitting process, the various immobilization procedures, kinetics, deactivation kinetics, New immobilized lipases for chiral resolution, reactor configurations, and process considerations are all reviewed and discussed.