• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.67-71
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• 2001

Most of the Cyclodextrin glucanotransferase (Gtases) which have been produced from B. subtilis were found to be excreted from the cells during cultivation. Immobilized whole cell CGTase from B. subtilis was prepared by encapsulating the broth solution which had been concentrated ten times with a rotary vacuum evaporator. Cyclization activity of CGTase was reduced by about 10% during the concentrating process, however, its transglycosylation activity, to convert xylitol to glucosyl-xylitol, using dextrin as glucosyl donor, increased by a factor of 3 or 5.

• 한국연초학회지
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• 제24권2호
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• pp.94-100
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• 2002

Cyclodextrin glucanotransferase from Bacillus stearothemophilus and Bacillus macerans synthesized maltol and ethyl maltol monoglucoside, with a series of its maltooligo-glucosides by transglycosylation with dextrin as a donor, and maltol or ethyl maltol as an acceptor. The monoglucoside formed from reaction mixture of maltol or ethyl maltol by the successive actions of Bacillus stearothemophilus cyclodextrin glucanotransferase and Rhizopus glucoamylase was isolated by Diaion HP-20 column and silica gel column chromatography. The structure of the isolated monoglucoside was identified as maltol-$\alpha$-D-glucoside and ethyl maltol-$\alpha$-D-glucoside, respectively, by FAB-MS, UV, $^1$H-NMR, $^{13}$ C-NMR spectra and products by hydrolysis with acid, $\alpha$ - and $\beta$ -glucosidases.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.425-431
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• 1995

A kinetic model of the cyclodextrin formation in a heterogeneous enzyme reaction system using swollen extrusion starch as substrate was derived emphasing the structural features of extrusion starch. The degree of gelatinization, the ratio of accessible and inaccessible portion of extrusion starch, adsorption of CGTase on swollen starch, the structural transformation during reaction, and product inhibition caused by produced CDs were considered in deriving kinetic model. Various kinetic constants were also evaluated. The derived kinetic equation was numerically simulated, which result showed that the derived kinetic equations can be used to predict the experimental data reasonably well under the various experimental conditions. Kinetic model can be utilized for the optimization of enzyme reactor and the process development for CD production from swollen extrusion starch.

• 한국연초학회지
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• 제25권2호
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• pp.120-127
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• 2003

Cyclodextrin glucanotransferase (CGTase) from Bacillus stearothermophilus synthesized vanillin and ethyl vanillin monoglucoside, with a series of its maltooligoglucosides by transglycosylation with dextrin as a donor, and vanillin or ethyl vanillin as an acceptor. The monoglucoside formed from reaction mixture of vanillin or ethyl vanillin by the successive actions of CGTase and Rhizopus glucoamylase was isolated by extraction with n-butanol saturated with water and silica gel column chromatography. The structure of the isolated monoglucoside was identified as vanillin- $\alpha$ -D-glucoside and ethyl vanillin- $\alpha$ -D-glucoside, respectively, by FAB-MS, UV, IR, 1H-NMR, 13C-NMR spectra and products by hydrolysis with acid, $\alpha$ - and $\beta$ -glucosidases.

• KSBB Journal
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• 제15권1호
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• pp.35-41
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• 2000

Xylitol을 당수용체로하여 당알콜 올리고당 gluosyl-xylitol을 생산하기 위하여 갭술고정화 전세포 CGTase를 제조하고자 하였다. CGTase를 생산하기 위하여 Bacillus macerans를 배양하는 경우 organic form의 질소원을 사용하는 경우 inorganic form의 질소원을 사용하는 경우보다 더 많은 CGTase를 생산하였고 배양도중 탄소원인 starch가 분해되는 동안 CGTase가 생성되었다. B. macerans에 의하여 생산된 CGTase는 80% 이상이 extracellular cnzyme 이며, intracellular enzyme은 20% 이내이었다. E. coh, C. glutamicum, S. cerevisiae 등과 달리 캡슐내부에 B. macerans를 접종하고 캡슐내부에서 고농도로 배양할 수 없었다. 배양액속에 존재하는 CGTase는 다른 이온성 물질들로 인하여 활성탄, Ambolite, Sephadex 등의 흡착제에 흡착시킬 수 없었다. 미생물을 배양한 배양책 전체를 10배로 농축하여 캡슐내에 고정화함으로써 캡슐고정화 전세포 CGTase를 제조할 수 있었다. 농축배양액을 이요하여 제조된 캡슐고정화 전세포 CGTase는 hydrolysis, intermolecular transglycosylation을 수행하였으며, xylitol을 당수용체로 하고 dextrin을 당공여체ㅗ 하여 glucosyl-xylitol을 생산하였다.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.710-713
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• 1998

A material with the same high performance liquid chromatography (HPLC) retention profile as authentic ascorbic acid 2-Ο-$\alpha$-glucoside (AA-2G) was detected in kimchi. This material was identified as AA-2G by testing its susceptibility to $\alpha$-glucosidase hydrolysis, the HPLC profile, and through the elementary analysis. Among several strains of bacteria isolated from fermented kimchi, four strains could produce cydodextrin glucanotransferase (CGTase) which catalyzes the transglucosylation reaction of ascorbic acid. By using starch as the glycosyl donor, AA-2G was produced as the major product through this reaction.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1678-1683
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• 2006

A novel suspension-phase enzyme reaction system for the intermolecular transglycosylation of L-ascorbic acid into 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid supplementing extrusion starch as the glycosyl donor was developed using cyclodextrin glucanotransferase from Thermoanaerobacter sp. A high conversion yield compared to the conventional soluble-phase enzyme reaction system using cyclodextrins and soluble starch was achieved. The optimal reaction conditions were 2,000 units of cycIodextrin glucanotransferase, 20 g/l of L-ascorbic acid, and 50 g/l of extrusion starch at $50^{\circ}C$ for 24 h. The new suspension-phase enzyme reaction system also exhibited several distinct advantages other than a high conversion yield, including a lower accumulation of oligosaccharides and easily separable residual extrusion starch by centrifugation or filtration in the reaction mixture, which will facilitate the purification of 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid. The new suspension-phase enzyme reaction system seems to be potentially applicable as the industrial process for the production of thermally and oxidatively stable 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.206-209
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• 2002

Bacillus stearothermophilus의 CCTase 유전자(cgtS) 대장균과 효모의 shuttle vector로서 항구적 promoter인 adh l promoter를 함유한 pVT103-U(6.9Kb)에 도입하여 재조합 plasmid pVT-CCTS (9.0Kb)을 구축하고 효모 숙주 S. cerevisiae 2805에서 발현시켰다. 재조합 균주의 항구적 발현계인 2805/pv7-CGTS의 최적 발현조건은 YP배지에 dextrose 2%, pH 5.5, 30"C에서 최적 발효조건이었으며, CCTase의 최대 발현량은 48시간 배양시 0.624unit/mL을 나타내었다. B. stearothermophilus의 signal peptide가 재조합 효모에서도 높은 분비효율을 나타내어서 발현된 효소의 87%가 세포 외로 분비 생산되었다.산되었다.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.251-257
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• 1998

Cycloinulooligosaccharide fructanotransferase (CFTase) which produces cyclofructan from inulin was purified 332-fold from a culture broth of Bacillus macerans CFCl. The molecular mass of the CFTase was estimated to be 110 kDa by SDS-polyacrylamide gel electrophoresis and gel filtration, indicating that the enzyme has a monomer structure. The maximal level of enzyme activity was observed at pH 7.5 and $45^{\circ}C$. The enzyme was stable in the pH range 6.0 to 9.5, and at temperatures up to $45^{\circ}C$ for 1 h. The enzyme activity was completely inhibited in the presence of 0.5 mM $Ag^+\;or\;Cu^2+$ ion. None of sucrose (GF), l-kestose (GF2), or nystose (GF3) were found to be substrates for the CFTase, but inulooligosaccharides larger than nystose were attacked by the enzyme. The CFTase catalyzes not only the cyclization as the major reaction, but also disproportionation and coupling reactions involving intermolecular transfructosylation in the same manner as cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19).

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.225-229
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• 1998

Formation of a L-Ascorbic Acid 2-O-$\alpha$-glucoside(AA-2G) is a chemically stable dervative of asocrbate that shows a vitamin C acitivity in vitro as well as in vivo. We studied whether ascorbic acid(AA) and AA-2G are formed in baechu kimchi during fermentation at 4 $^{\circ}C$ or 18$^{\circ}C$. To determine the formation of AA and AA-2G during fermentation of kimchi, wheat flour (as a carbhydrate source) added baechu kimchi (WBK) and control baechu kimchi(CBK) were prepared and fermented at 4 $^{\circ}C$ or 18 $^{\circ}C$. A substance like AA-2G was detected by HPLC from WBK fermented at 18 $^{\circ}C$ for 26 days in fall season and confirmed later to be the AA-2G showing distinctive characteristics of heat stability and resistance to ascrobate oxidase catalase. However, none of the kimchi formed AA-2G when the kimchi were fermented under a different temperature condition such as 4 $^{\circ}C$ instead of 18 $^{\circ}C$ or a different season such as summer instead of fall even if they were fermented at 18 $^{\circ}C$. The pH of kimchi was decreased rapidly during the first 3 days. and then decreased slowly after 4 days when the kimchi were fermented at 18 $^{\circ}C$. However, there were slight changes of pH in both CBK and WBK feremented at 4$^{\circ}C$ for 30 $^{\circ}C$ days. Therefore, the AA-2G -forming activity in kimchi seems to be correlated with the formentation temperature, the microorganisms involved in kimchi fermentation and a suitable glycosyl donor for AA as provided by wheat flour in this study.