• Mycobiology
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• 제29권4호
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• pp.183-189
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• 2001

Extracellular amylase properties were examined with the mycelium of Tricholoma matsutake isolated from ectomycorrhizal roots of Pinus densiflora. The molecular weights of $\alpha$-amylase and glucoamylase were estimated as 34.2 kD and 11.5 kD, respectively, after eluted through Superdex 75 column. The optimum pH of the purified enzyme was found in a range of pH $5.0{\sim}6.0$, with a peak at pH 5.0. The activities of these enzymes were stable from $4^{\circ}C\;to\;30^{\circ}C$. The $\alpha$-amylase of T. matsutake readily hydrolyzed soluble starch and amylose-B, while it weakly hydrolyzed glycogen, dextrin, amylose and amylose-A. The main products of hydrolysis were confirmed to be glucose, maltose and maltotriose on the basis of the similarities in the thin layer chromatographic mobility.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1991년도 춘계학술발표대회 논문집
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• pp.225-236
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• 1991

The genes encoding the thermostable $\alpha$-amylase and maltogenic amylase from Bacillus lichenciformis were cloned and expressed in E. coli. The recombinant plasmid pTA322 was found to contain a 3.1kb EcoRI genomic DNA fragment of the thermostable $\alpha$-amylase. The cloned $\alpha$-amylase was compared with the B. licheniformis native $\alpha$-amylase. Both $\alpha$-amylase have the same optimal temperature of $70^{\circ}C$ and are stable in the pH range of 6 and 9. The complete nucleotide sequences of the thermostable $\alpha$-amylase gene were determined. It was composed of one open reading rame of 1,536 bp. Start and stop codons are ATG and TAG. From the amino acid sequence deduced from the nucleotide sequence, the cloned thermostable $\alpha$-amylase is composed of 483 amino acid residues and its molecular weight is 55,200 daltons. The content of guanine and cytosine is $47.46mol\%$ and that of third base codon was $53_41mol\%$. The recombinant plasmid, pIJ322 encoding the maltogenic amylase contains a 3.5kb EcoRI-BamHI genomic DNA fragment. The optimal reaction temperature and pH of the maltogenci amylase were $50^{\circ}C$ and 7, respectively. The maltogenic amylase was capable of hydrolysing pullulan, starch and cyclodextrin to produce maltose from starch and panose from pullulan. The maltogenic amylase also showed the transferring activity. The maltogenic amylase gene is composed of one open reading frame of 1,734bp. Start and stop codons are ATG and ATG. At 2bp upstream from start codon, the nucleotide sequence AAAGGGGGAA seems to be the ribosome-binding site(RBS, Shine-Dalgarno sequence). A putative promoter(-35 and-10 regions) was found to be GTTAACA and TGATAAT. From deduced amino acid sequence from the nucleotide srquence, this enzyme was comosed of 578 amino acid residues and its molecular weight was 77,233 daltons. The content of guanine and cytosine was $48.1mol\%$. The new recombinant plasmid, pTMA322 constructed by inserting the thermostable $\alpha$-amylase gene in the EcoRI site of pIJ322 to produce both the thermostable $\alpha$-amylase and the maltogenic amylase were expressed in the E. coli. The two enzymes expressed from E. coli containing pTMA322 was reacted with the $15\%$ starch slurry at $40^{\circ}C$ for 24hours. The distribution of the branched oligosaccharides produced by the single-step process was of the ratio 50 : 50 between small oligosaccharide up DP3 and large oligosaccharide above DP3.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.183-188
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• 1992

A soil bacterium which produces raw starch-digesting $\beta$-amylase in culture medium, has been screened from soils. One strain, isolated and identified as Bacillus polymyxa No. 26, was selected as a $\beta$-amylase producing bacterium. Morphological and biological characteristics of the strain were found to be similar to those of a strain belonging to B. polymyxa. The electron microscopic observations of the bacterial vegetative cells and sporulated cells were extensively done to know the corelation between the enzyme synthesis and sporulation. When the bacterium was cultured on the appropriate media (3% dextrin, 0.3% beef extract, 0.5% polypeptone, 1% yeast extract and 0.3% NaCl at pH 7.0 for 4 days) raw starch-digestible $\beta$-amylase was produced extracellularly. This strain produced 130 units of $\beta$-amylase per ml in a culture medium containing 3% dextrin at $30^\circ{C}$. This value is compared to those of other $\beta$-amylase-producing strains. The optimum pH and temperature for crude enzymes were pH 6.5 to 7.0 and $50^\circ{C}$, respectively. The enzymes were stable between pH 5.5 and 9.0 for 30 min at $45^\circ{C}$.

• 한국식품과학회지
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• 제37권2호
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• pp.189-193
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• 2005

팥 1차, 2차 및 3차 침출액의 조사포닌 함량은 각각 0.82, 1.44 및 1.52mg/g으로서 침출 횟수가 늘어남에 따라 증가하였다. 팥 침출액에 ${\alpha}-amylase$ 처리시 ${\circ}Brix$가 $1.0{\circ}Brix$ 정도 증가하였으며, ${\circ}Brix$의 증가는 효소처리보다 침출 횟수에 의해 더 큰 영향을 받았다. 침출액의 pH는 효소처리에 의해 감소하는 경향을 나타냈으며 3차 침출액에 ${\alpha}-$와 ${\beta}-amylase$를 동시 처리한 경우 pH 4.7로서 대조구(pH 6.2)보다 많이 낮아졌다. 색도의 경우 일반적으로 효소처리에 의해 침출액의 L값이 감소하고 a와 b 값은 모두 증가하는 경향을 보였으며 이는 육안으로 충분히 관찰할 수 있었다. 팥의 3차 침출액을 사용하여 음료 시제품을 제조한 결과 관능적인 면에서 적용이 가능한 것으로 판단되었다.

• 미생물학회지
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• 제42권2호
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• pp.160-163
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• 2006

현미는 백미에 비하여 식품영양학적 가치 및 식이섬유의 함유량이 높은 쌀겨 및 배아를 포함하고 있으나 소화가 잘되지 않는 단점 이 있다. 따라서 발효현미는 소화력을 높임과 동시에 좋은 영양 공급원이 될 수 있으므로 높은 amylase와 pretense의 활성으로 현미를 발효할 수 있는 미생물을 선별하였다. 2.5%(w/v)의 현미분말을 유일한 영양원으로 한 액체배지를 생장배지로 사용하여 생장능력과 효소 생산능력을 조사하였다. 조사한 8종의 Bacillus 와 11종의 유산균 중에서 모든 Bacillus 균주와 두 종의 유산균이 생장과 효소활성을 보였다. 생균수는 $10^7CFU/mL$을 초과하였으며 Bacillus sp. Bacillus sp. B2, Bacillus sp. B11, Leuconostoc gelidum, Pediococcus pentosaceus 가 생산하는 최고 amylase 활성은 각각 17.85, 17.50, 17.10, 17.10, 3.24 U/ml이었고, 최고 pretense 활성은 각각 22.48, 22.04, 23.76, 12.13, 3.80 U/ml이었다. 따라서 이 균주들은 발효 현미 제조를 위한 접종균주로서 이용이 가능하리라 사료된다.

• 미생물학회지
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• 제35권4호
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• pp.296-301
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• 1999

충남 아산시 호서대 주변 토양에서 Bacillus 균주를 분리하고, 생화학적 검사, VITEK, MIDI system을 이용해 Bacillus licheniformis B1으로 동정하였다. B. licheniformis B1은 amylase와 protease를 세포 외로 분비하였다. 본 균주를 증자 대두에 접종해서 청국장과 간장발효 과정을 추적하였다. 당과 아미노산의 항산화물질로 알려져 있는 갈변물질이, 청국장 발효에서는 초기에 비해 8배 이상, 간장에서는 2배 이상 증가하였다. 또한 청국장 발효에서는 단백질 분해효소의 활성이 발효시작 하루만에 최대치에 이르렀다. 간장발효에서는 단백질 분해효소의 활성이 발효시작 하루만에 50% 감소했으나 그 후로는 일정한 값을 유지하였는 데, 이는 salt의 영향으로 보인다. 또한 청국장과 간장이 발효되면서, 증자대두에 존재하지 않던 안정된 고분자 핵산이 확인되었다. 호서대 주변 토양에서 분리한 B. licheniformis B1으로, 청국장과 간장발효를 연속적이면서 성공적으로 수행할 수 있음을 본 연구를 통해 확인하였고, 아울러 갈변물질과 핵산 기능성 물질의 개발 가능성을 제시하였다.

• 한국식품과학회지
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• 제23권3호
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• pp.349-354
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• 1991

자연계로부터 알칼리성 아밀라아제 활성이 높은 Bacillus sp. GM8901 균주를 분리하여 균을 동정하였으며 그 조효소액을 이용하여 알칼리성 아밀라아제의 몇 가지 성질을 조사하였다. Bacillus sp. GM8901 균주의 특성을 조사해본 결과 B. licheniformis와 비슷한 것으로 나타났으며 $50^{\circ}C$에서 균의 성장과 효소생산이 최대였으며 알칼리성 아밀라아제는 inducible 효소였다. Bacillus sp. GM8901 은 pH 10.5 부근에서 가장 잘 자라는 호알칼리성 균주였으며 효소생산도 최대치를 나타내었다. 조효소액을 이용하여 실험한 결과 알칼리성 아밀라아제의 최적온도는 $50{\sim}60^{\circ}C$, 최적 pH는 $pH\;10{\sim}12$였으며 비교적 $50^{\circ}C$까지 열에 안정하였고 $pH\;3{\sim}12$까지 효소의 안정성이 유지되는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.293-298
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• 1997

A 4.6-kb HindIII fragment encompassing the complete 140-kDa ${\alpha}$-amylase gene of Lactobacillus amylovorus B 4540 was cloned into pBR322 by the shot gun method. Southern blotting and restriction mapping for the insert were performed. The recombinant 9.0-kb plasmid, pFML1, conferred ${\alpha}$-amylase activity to E. coli and Lactococcus lactis hosts when introduced by electroporation. SDS-PAGE and zymography confirmed the production of 140-kDa ${\alpha}$-amylase and its proteolytic degradation products with enzyme activity in transformants. Total ${\alpha}$-amylase activity of E. coli $DH5{\alpha}$ cells harboring pFML1 was 1.8 units and most activity was detected from cell pellets. Total enzyme activity of L. lactis subsp. lactis MG1363 transformant was five to ten-fold lower than that of E. coli cell but more than half of the activity was detected in the culture supernatant.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1044-1049
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• 2000

Three wethers fitted with silastic catheters for collection of pancreatic juice, and cannulas located in the abomasum and the duodenum were used to investigate the effects of different hay and energy intake on pancreatic exocrine secretion. The wethers were fed Italian ryegrass hay or alfalfa hay at maintenance energy requirement and alfalfa hay ad libitum. High energy intake from alfalfa significantly increased abomasal flow of dry matter and both the concentration and daily secretion of ${\alpha}-amylase $. The high energy intake also tended to increase daily secretion of lipase, trypsin and chymotrypsin through the large volume of pancreatic juice. Compared with Italian ryegrass hay, alfalfa hay at the maintenance decreased abomasal dry matter flow, but increased concentration of ${\alpha}-amylase $ in the pancreatic juice, and tended to increase daily secretion of ${\alpha}-amylase $. The secretion of the other enzymes was not different between the two hays at maintenance intake. These results suggest that the kind of hay could change the concentration of ${\alpha}-amylase $ in the pancreatic juice, and that the intake level of alfalfa hay affects the ${\alpha}-amylase $ concentration and the juice volume secreted from the pancreas.

• 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.