• Title/Summary/Keyword: cyclodextrin glucanotransferase

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Reaction Mechanism of Transglycosylation of Stevioside in the Attrition Coupled Reaction System Using Raw Starch as a Glycosyl Donor (생전분을 당공여체로 한 분쇄마찰매체 함유 효소반응계에서의 Stevioside의 당전이 반응 기작)

  • Baek, Seung-Gul;Park, Dong-Chan;Huh, Tae-Lin;Lee, Yong-Hyun
    • Microbiology and Biotechnology Letters
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    • v.22 no.3
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    • pp.252-258
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    • 1994
  • Transglycosylation of stevioside in the attrition coupled heterogeneous reaction system using raw starch as a glycosyl donor has significant advantages over conventional reaction systems using liquefied starch as a donor. The transglycosylation of stevioside under the presence of organic solvent showed that transglycosylation reaction occurs via two steps ; initially from raw starch to cyclodextrin(CD), and then followed by transglycosylation of produced CD. Comparison of the transglycosylation efficiency of c$\alpha $-, $\beta $, $\gamma $-CDs indicated that $\alpha $-, $\beta $-CD are mainly utilized as a glycosyl donor for following reaction. The reaction mechanism of transglycosylation between stevioside and CD proceeded according to random sequential bireactant mechanism. The equilibrium constant of transglycosylation reaction of cyclodextrin glucanotransferase wase also evaluated. The structure of transglycosylated stevioside was confirmed by TLC, and it was found that glycosyl group(G$_{1}, $ ~ G$_{4}$-glycosidic bond.

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Optimization of Cyclodextrin Glucanotransferase Immobilization on Amberlite IRA-900 (Amberlite IRA-900을 이용한 cyclodextrin glucotransferase의 최적 고정화)

  • Seo, Hyo-Jin;Jung, Il-Hyong;Nam, Soo-Wan;Kim, Byung-Woo;Kim, Sung-Koo
    • Journal of Life Science
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    • v.14 no.5
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    • pp.794-799
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    • 2004
  • Cyclodextrin glucanotransferase (CGTase) produced by Bacillus subtilis NAl/pKBl was used for the production of cyclodextrin (CD). The enzyme was purified by ion exchange and gel filtration chromatography. The purified enzyme exhibited its maximum activity in the pH range of 6.0 to 7.0 and temperature range of 60 to $70^{\circ}C$. Immobilization of purified CGTase was carried out with various immobilization matrices. Amberlite IRA-900, a strong basic anion exchange resin, showed the highest immobilization ability (38 units per gram resin). Optimal pH and temperature for enzymatic reaction of the immobilized CGTase were pH 6.0 and 60t. The activity of immobilized CGTase maintained more than a month and could be reused for a month in a continuous enzyme reactor for the production of CD.

Effect of C- or D-Domain Deletion on Enzymatic Properties of Cyclodextrin Glucanotransferase from Bacillus stearothermophilus NO2

  • Jeon, Sung-Jong;Nam, Soo-Wan;Yun, Jong-Won;Song, Seung-Koo;Kim, Byung-Woo
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.152-157
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    • 1998
  • To analyze the role of the C and D domains in the cyclization activity of cyclodextrin glucanotransferase (CGTase), two plasmids, pKB1ΔC300 and pKB1ΔD96, were constructed in which DNA regions encoding 100 and 32 amino acids, respectively, from the C and D domains of B. stearothermophilus NO2 CGTase were deleted. The mutated CGTase from the pKBlΔC300 produced much lower amounts of ${\alpha}$-, ${\beta}$-, and $\gamma$-cyclodextrin (CD) than the parental CGTase. However, the mutated CGTase from the pKBlΔD96 showed a similar production pattern of CDs to wild-type CGTase. The production ratios of the ${\alpha}$-, ${\beta}$- and $\gamma$-CDs were not affected by the deletions, when compared to those of parental CGTase. The optimum temperature of the mutated CGTase from the pKBlΔC300 was decreased from $60^{\circ}C$ to $55^{\circ}C$. The optimum pH of the mutated CGTase from the pKB1D96 was shifted from 6.0 to 7.0. The thermostability of the two mutant CGTases were not changed. From these results, it is suggested that the C and D domains are not related to cyclization activity directly because mutant-enzymes deleted C or D domains still possessed their activity. However, they are important for other enzymatic properties such as productivity and pH optimum as a partition of CGTase tertiary structure.

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Production and Characterization of Cyclodextrin Glucanotransferase fronm Bacillus sp. JK-43 Isolated from Kimchi (김치 분리균인 Bacillus sp. JK-43이 생산하는 Cyclodextrin Glucanotransferase의 생산 및 특성)

  • Jun, Hong-Ki;Bae, Kyung-Mi;Kim, Young-Hee;Baik, Hyung-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.1
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    • pp.41-48
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    • 2000
  • A bacterial strain, designated as JK-43, producing extracellular cyclodextrin glucanotransferase (CGTase)[EC 2.4.1.19] was isolated from kimchi. The CGTase from isolated strain JK-43 showed the transglucosylation activity from soluble starch to L-ascorbic acid(AA) compared to those obtained from other strains. A main product formed by this reaction was identified as $2-O-{\alpha}-glucopyranosyl$ L-ascorbic acid(AA-2G) by testing its susceptibility to ${\alpha}-glucosidase$ hydrolysis, the HPLC profiles, and through the elementary analysis. the ${\beta}-CD,\;{\gamma}-CD$, potato starch and corn starch were identified to be suitable glucosyl donor for transglucosylation reaction on AA by CGTase. Acceptor specificity on AA-2G production was examined by use of AA, Iso-AA and AA-2P. Transglucosylation was observed toward AA-2P as well as AA and Iso-AA. The microorganism isolated from kimchi was identified as a strain of Bacillus sp. JK-43 based on the morphological, cultural, biochemical characteristics and partial 16SrDNA sequence analysis. The maximal CGTase production was observed in a medium containing 1.0% soluble starch, 1.0% yeast extract, 1.0% $Na_2CO_3\;0.1%\;K_2HPO_4,\;and\;0.02%\;MgSO_4{\cdot}7H_2O$ with initial pH 7.0. The strain was cultured at $37^{\circ}C$ for 26 hrs with reciprocal shaking.

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Immobilization of Cyclodextrin Glucanotransferase for Production of 2-O-\alpha-D-Glucopyranosyl L-Ascorbic Acid. (2-O-\alpha-D-Glucopyranosyl L-Ascorbic acid 생산을 위한 Cyclodextrin glucanotransferase의 고정화)

  • 성경혜;김성구;장경립;전홍기
    • Microbiology and Biotechnology Letters
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    • v.31 no.4
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    • pp.368-376
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    • 2003
  • Cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JB-13 was immobilized on various carriers by several immobilization methods such as ionic binding, covalent linkage and ultrafiltration to improve the process performance. The ultrafiltration and covalent linkage with CNBr-activated sepharose 4B were found as the best method for immobilization of CGTase. The ability of CGTase immobilization onto CNBr-activated sepharose 4B was as high as 18,000 units/g resin when the conditions was as follows: contact time 9 hrs at $37^{\circ}C$, pH 6.0, 100 nm and enzyme loading 24,000 units/g resin. The optimum conditions for production of 2-O-$\alpha$-D-Glucopyranosyl L-Ascorbic acid by immobilized CGTase turned out to be: pH 5.0, temperature $37^{\circ}C$, 20% substrate solution containing 8% (w/v) of soluble starch and 12% (w/v) of L-ascorbic acid sodium salt, 100 rpm, far 25 hrs and with 800 units of immobilized CGTase/ml substrate solution. Moreover the CGTase activity could be stably maintained for 8 times of repetitive reactions after removing products by ultrafiltration through YM 10 membrane.

Production of Cyclodextrin Glucanotransferase from Aspergillus sp. CC-2-1 and its Characterization (Aspergillus sp. CC-2-1에 의해 생산되는 Cyclodextrin Glucanotransferase의 생산 및 특성)

  • Cho, Young-Je;Kim, Myoung-Uk
    • Korean Journal of Food Science and Technology
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    • v.32 no.5
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    • pp.1158-1167
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    • 2000
  • To produce ${\beta}-cyclodextrin({\beta}-CD)$, a cyclodextrin glucanotransferase(CGTase) producing Aspergillus sp. CC-2-1 was isolated from soil. The enzyme was purified and its enzymological characteristics were investigated. It was found that production of CGTase reached to the maximum when the wheat bran medium containing 0.1% albumin, 2% $(NH_4)_2S_2O_8$, 2% soluble starch and 0.2% $KH_2PO_4$ was cultured for 5 days at $37^{\circ}C$. The purity of CGTase was increased by 13.14 folds after DEAE-cellulose ion exchange chromatography and Sephadex G-100, G-150 gel filtration and the specific activity was 172.14 unit/mg. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. The molecular weight of CGTase was estimated to be 27,800 by Sephadex G-100 gel filtration and SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for the CGTase activity were 9.0 and $80^{\circ}C$, respectively. The enzyme was stable in pH $8.0{\sim}11.0$ at $60{\sim}80^{\circ}C$. The activity of purified enzyme was activated by $K^+,\;Cu^{2+}$ and $Zn^{2+}$. The activity of the CGTase was inhibited by the treatment with 2,4-dinitrophenol and iodine. The result suggests that the purified enzyme has phenolic hydroxyl group of tyrosine, histidine imidazole group and terminal amino group at active site. The reaction of this enzyme followed typical Michaelis-Menten kinetics with the $K_m$ value of 18.182 g/L with the $V_{max}$ of 188.68 ${\mu}mole/min$. The activation energy for the CGTase was calculated by Arrhenius equation was 1.548 kcal/mol.

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Expression and Optimum Production of Cyclodextrin Glucanotransferase Gene of Paenibacillus sp. JB-13 in E. coli (Paenibacillus sp. JB-13 Cyclodextrin Glucanotransferase 유전자의 E. coli 에서의 발현 및 최적 생산)

  • Kim, Hae-Yun;Lee, Sang-Hyeon;Kim, Hae-Nam;Min, Bok-Kee;Baik, Hyung-Suk;Jun, Hong-Ki
    • Korean Journal of Microbiology
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    • v.44 no.1
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    • pp.74-79
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    • 2008
  • The purpose of this study is to clone cgt gene from Paenibacillus sp. JB-13 and to overexpress the protein in E. coli. For this purpose, the cgt gene was amplified from Paenibacillus sp. JB-13 genomic DNA by PCR using degenerate oligonucleotide primers. The sequence analysis results showed that the cgt gene from Paenibacillus sp. JB-13 has 98% homology with the cgt gene of Bacillus sp. To overexpress the protein, the cgt gene was cloned into pEXP7 expression vector and transformed into E. coli. The production of CGTase by recombinant E. coli was optimized under following conditions: 0.5% glucose, 3.0% polypeptone, 0.3% $K_2HPO_4$, 0.5% NaCl, and 7.0 of initial pH, 2.0% of inoculum, $37^{\circ}C$ of culture temperature for 14 hr. And the optimal agitation was found at 0.1 vvm. The synthesis of 2-O-${\alpha}$-D-Glucopyranosyl L-Ascorbic acid (AA-2G) using the CGTase expressed in E. coli was identified as AA-2G by HPLC and HPLC confirmed that treating AA-2G made by cloned CGTase with ${\alpha}$-glucosidase substantially produced AA and glucose.