• 한국식품영양학회지
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• 제10권3호
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• pp.360-364
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• 1997

멥쌀식혜에 Saccharomyces cerevisae를 가해 28$^{\circ}C$에서 10일간 발효시켜서 식혜주를 제조하였다. TLC 및 HPLC 분석 결과 발효에 따라 글루코오스는 하루, 말토오스는 4일, 말토트리오스는 6일까지만 존재하였다. 그러나, 분자량이 큰 말토올리고당과 한계덱스트린은 발효되지 않았다. 에탄올은 6.5%를 나타냈다. 식혜주의 아미노산 함량은 2.9$\mu$mol/ml, 단백질 함량은 457$\mu\textrm{g}$/ml를 나타냈다. pH는 3.67, 산도는 3.1ml를 나타냈다. 한계덱스트린은 1H-NMR로 분석 결과 식혜에 존재하는 것과 구조상 변화가 없었다. $\alpha$-1,4-결합에 대한 $\alpha$-1,6-결합의 비율도 5.6:1을 나타냈다. 관능검사 결과, 맛은 와인과 비슷하였다.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.71-76
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• 1997

Pullulanase was produced from the Klebisella pneumonias NFB_320 with the conmposition of 0.1% pullualn 1.5% yeast extract, 0.2% $K_2$HPO$_4$ and 0.02% MgSO$_4$.7$H_2O$(pH5.5). The optimum temperature for activity of the pulluanase was 3$0^{\circ}C$ and the highest yield of the enzyme was obtained after cell growth at 3$0^{\circ}C$ for 18hr, and maintained until 24hr cultivation. The pullulanase was successively purified 52.6 folds with 7.8% yield by acetone precipitation. DEAE-cellulose column chromatography and gel fitrations. The purified enzyme hydrolyzed pullulan into maltotriose exclusively. Chemical and physical properties of purified pullulanase from Klebisella pneumonias NFB-320 were examined. The optimum pH and temperature for enzyme activity were 5.0 and 6$0^{\circ}C$, respectively. The enzyme was stable between pH4 and 7, and up 5$0^{\circ}C$. The effect of mo-dification on the rate of enzyme reaction was studies with various chemicals and metal ions. The enzyme has been found to be inactivated by I$_2$ and N-bromosussinimide(NBS), which probably indicated the involve- ment of tryptophan residues in the active center of the enzyme.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.298-302
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• 1993

Pullulan was produced from starch hydrolysate with Aureobasidium pullulans SH8646. We could measure the correct amount of pullulan produced without the interference of starch from the culture supernatant by using a bacterial $\alpha$-amylase treatment and ethanol: acetone (1:1) precipitation. When 5% acid-hydrolyzed starch was used as a carbon source, the dry cell weights obtained were similar irrespective of DE values of starch hydrolysates. The dry cell weights of those on the starch hydrolysate media prepared with 0.1 N HC1 treatment, were slightly higher (9.5~10.5 g/l) than those on the starch hydrolysate media prepared with 1.0 N HCl (8.5~9.5 g/l). And among the starch hydrolysates showing DE values lower than 50, maximum pullulan production of 15 g/l was obtained at DE 30~40 starch hydrolysate but those showing DE values higher than 50, the pullulan production was increased with the increase of the DE value of starch hydrolysates. From the media containing 5%, 10%, and 15% starch hydrolysate (DE 25, 45, and 75), about 20~34% pullulan yield was obtained and the maximum pullulan yield of 34% (17g/l) was obtained from 5% DE 75 starch hydrolysate. The pullulan yields from starch hydrolysate media were much lower than those from glucose, maltose, maltotriose, and sucrose media.

• 한국미생물·생명공학회지
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• 제27권2호
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• pp.129-135
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• 1999

EH-1 was highest at 9 days of incubation. This regrowth and enzymatic activity of Haloarcular sp. EH-1 was highest at 9 days of incubation. This amylase was purified by acetone fractionation, DEAG-Cellulose column chromatography, 1st Sephadex G-75 gel filtration, CM-Cellulose column chromatography and 2nd Sephadex G-75 gel filtration. The amylase was purified about 98.64 fold with a yield of 11.75%. The molecular weight of amylase was estimated to be about 43,000and 40,000 by gel filtration and SDS-polyacrylamide gel electrophoresis, respectively, suggesting that the enzyme was a monomer. Amylase had an optimal temperature of 4$0^{\circ}C$, and an optimum pH of 7.0, and the thermal stability was observed the above 50% at 10$0^{\circ}C$ after 1 hour, and the stable range of pH was 6.0 to 8.0. The enzymatic activity was increased in the presence of 10 mM 2-mercaptoethanol, slightly by 10 mM SnCl2.2H2O.FeCl2.4H2O.CuCl2.2H2O.HgCl2.6H2O and SDS. End products from soluble starch were glucose, maltose and maltotriose, and Km value for soluble starch was 2.5mg/ml.

• Food Science and Biotechnology
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• 제14권5호
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• pp.681-684
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• 2005

A maltopentaose-producing amylase (G5-amylase) from Bacillus megaterium KSM B-404 was applied to retard bread retrogradation. Retrogradation rates were determined by differential scanning calorimetry. Gel permeation chromatography determined changes in maltooligosaccharide composition and the molecular weight profiles of carbohydrate tractions. The baking process produced maltopentaose and maltotriose by the hydrolysis of starch molecules into small units. Amylose and amylopectin degradation as well as maltooligosaccharides produced by the enzyme were likely responsible for retarding starch retrogradation. Overall, addition of G5-amylase reduced the starch retrogradation rate, and was as effective as Novamyl(R), a commercial enzyme.

• 한국식품조리과학회지
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• 제7권4호
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• pp.51-61
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• 1991

Physical and chemical properties of glycosylsucrose were characterized as follows: 1. The moisture content of glycosylsucrose syrup (35% , w/w) was 63.6% and total sugar in solid was 35.9%. 2. Main sugar compositions of glycosylsucrose syrup were maltotetraose 54.5%, sucrose 18.0%, glycosylsucrose 15.3%, maltosylsucrose 11.3% and the content of glucose, maltose, maltotriose and fructose were very little. 3. Perceived sweetness threshold of glycosylsucrose was 0.71%, relative sweetness was 0.53, and sweetness intensity expressed as power function was S=$0.78^{\circ}$C^{1.5}$$. 4. Viscosity of glycosylsucrose was higher than that of sucrose and Japanese product at 10, 25, 35 and $65^{\circ}C$. 5. The content of water absorption of gylcosylsucrose at Aw 0.80 was 0.48 g $H_2$O/g dry weight while that of sucrose was 0.17g $H_2$O/g dryweight at Aw 0.86. 6. The stability of glycosylsucrose was decreased by acidic pH, high temperature and long heating time. 7. The glycosylsucrose showed very little browning when heated with pepton, but alkaline pH (pH8), high temperature and long heating time increased browning reaction.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.539-545
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• 2014

Styrene-acrylamide co-polymer was immobilized on porous partially sub-$2{\mu}m$ silica monolith particles and inner surface of fused silica capillary ($50{\mu}m$ ID and 28 cm length) to result in ${\mu}LC$ and CEC stationary phases, respectively, for separation of anomeric D-glucose derivatives. Reversed addition-fragmentation transfer (RAFT) polymerization was incorporated to induce surface polymerization. Acrylamide was employed to incorporate amide-functionality in the stationary phase. The resultant ${\mu}LC$ and CEC stationary phases were able to separate isomers of D-glucose derivatives with high selectivity and efficiency. The mobile phase of 75/25 (v/v) acetonitrile (ACN)/water with 0.1% TFA, was used for HPLC with a packed column (1 mm ID, 300 mm length). The effects of pH and ACN composition on anomeric separation of D-glucose in CEC have been examined. A mobile phase of 85/15 (v/v) ACN/30 mM sodium acetate pH 6.7 was found the optimized mobile phase for CEC. The CEC stationary phase also gave good separation of other saccharides such as maltotriose and Dextran 1500 (MW~1500) with good separation efficiency (number of theoretical plates ~300,000/m).

• Journal of Microbiology
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• 제43권6호
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• pp.561-568
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• 2005

A newly-isolated thermophilic strain of the zygomycete fungus Rhizomucor pusillus 13.36 produced highly active dextrinogenic and saccharogenic enzymes. Cassava pulp was a good alternative substrate for amylase production. Dextrinogenic and saccharogenic amylases exhibited optimum activities at a pH of 4.0-4.5 and 5.0 respectively and at a temperature of $75^{\circ}C$. The enzymes were highly thermostable, with no detectable loss of saccharogenic or dextrinogenic activity after 1 hand 6 h at $60^{\circ}C$, respectively. The saccharogenic activity was inhibited by $Ca^{2+}$ while the dextrinogenic was indifferent to this ion. Both activities were inhibited by $Fe^{2+}\;and\;Cu^{2+}$ Hydrolysis of soluble starch by the crude enzyme yielded $66\%$ glucose, $19.5\%$ maltose, $7.7\%$ maltotriose and $6.6\%$ oligosaccharides.

• 미생물학회지
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• 제36권2호
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• pp.112-118
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• 2000

Bacillus circulans KCT3004 유래의 호산성 $\alpha$-amylase 유전자가 pUC19을 vector로 하여 대장균 내에서 클로닝 되었다. 클로닝된 5.8kb Pst I DNA절편은 pUC19내에서의 삽입방향과는 무관하게 $\alpha$-amylans보다 약40배 정도의 높은 효소활성을 나타내었다. 본 연구에서 클로닝 및 발현된 효소의 최적 pH와 온도는 각각 pH 3.6 $45^{\circ}C$였으며, $40^{\circ}C$에서 1시간 동안의 사전 열처리에도 활성의 감소를 일으키지 않았다. 이 효소는 SDS-PAG와 zymogram을 통해 분석해 본 결과 분자량은 약 55,000으로 추정되었으며 기질로 starch만을 가수분해하여 maltoriose 이상의 올리고당 분자들을 주로 생산할수 있었다.

• 한국식품과학회지
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• 제27권4호
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• pp.605-611
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• 1995

호남지방에서 생산된 6점의 토종꿀을 대상으로 disaccharides와 trisaccharides를 분취한 다음 GC와 HPLC를 이용하여 각 oligosaccharides를 분리, 정량하였다. disaccharides는 토종꿀 중에 $5.9{\sim}8.4%$ 범위로 함유되어 있었는데 GC로 분석한 결과 sucrose, nigerose, maltose, laminaribiose, turanose, kojibiose, palatinose 및 isomaltose 등 8개의 당류가 분리되었으며, 그 중 maltose가 평균 2.28%로 가장 많이 함유되어 있었으며 그 다음으로 turanose가 평균 1.57%의 함량을 나타냈다. trisaccharides는 토종꿀 중에 $1.4{\sim}5.4%$ 범위로 함유되어 있었는데 isopanose, erlose, theanderose, maltotriose, panose 등 5개의 당류가 분리되었으며, 그 중 erlose가 평균 2.83%로 가장 많은 부분을 차지하고 있었다. 토종꿀중에 함유되어 있는 전체 oligosaccharides의 조성을 살펴보면 erlose가 가장 많이 함유되어 있었으며 maltose, turanose, sucrose, isomaltose의 순서로 많이 함유되어 있었다.