• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.296-302
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• 2012

A bacterial strain was isolated from soybean paste fermented in a Korean Buddhist temple as a producer of the extracellular thermostable ${\alpha}$-amylase. The isolate YB-1234 has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. A gene encoding the thermostable ${\alpha}$-amylase of B. licheniformis YB-1234 was cloned into Escherichia coli and its nucleotide sequence was determined. The deduced amino acid sequence of ${\alpha}$-amylase was very highly homologous to those of the thermostable ${\alpha}$-amylases of B. licheniformis belonging to the glycosyl hydrolase family 13. The ${\alpha}$-amylase produced by recombinant E. coli carrying the ${\alpha}$-amylase gene exhibited maximal activity at pH 6.0, identical to ${\alpha}$-amylase in the culture filtrate of B. licheniformis, while the temperature profile was somewhat different between the two. Particularly, ${\alpha}$-amylase produced from B. lcheniformis is much more thermostable than that from recombinant E. coli. The predominant products resulting from the ${\alpha}$-amylase hydrolysis were glucose, maltose and maltotriose for maltotetraose and maltohexaose.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.97-102
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• 2008

Four hundred and forty 1-day-old Arbor Acre broilers were fed commercial starter diets with 0, 250, 750 and 2,250 mg/kg of an alpha-amylase preparation from 1 to 21 days of age to investigate the effects of an exogenous enzyme on growth performance, activities of digestive enzymes in the pancreas and anterior intestinal contents and pancreatic amylase mRNA expression. Body weight gain (BWG) and average daily gain (ADG) increased linearly (p<0.01) with increasing levels of supplementary amylase but feed conversion ratio (FCR) was not affected. There was a negative quadratic change of protease and amylase in the small intestinal contents with the increase of supplementary amylase level. The activity of intestinal trypsin was also increased (p<0.05). Lipase was unaffected by amylase supplementation (p>0.05). The pancreatic protease, trypsin, and lipase were not affected by exogenous amylase levels. Consistent with the tendency for a linear depression of amylase activity, pancreatic ${\alpha}$-amylase mRNA was down-regulated by dietary amylase supplementation. The present study suggested that oral administration of exogenous amylase affected activities of intestinal enzymes and the production of pancreatic digestive enzymes in a dose-dependent manner.

• KSBB Journal
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• v.18 no.5
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• pp.363-370
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• 2003

A filamentous fungus, strain FM04 producing amylase was isolated from rotten yam peels and potatoes. The favorable conditions of cultivation factors such as, temperature, pH, and agitation speed of strain FM04 were 28∼30$^{\circ}C$, 5.0∼6.0, and 100 rpm, respectively. Starch was the best carbon source in the amylase production. Therefore, food wastes containing lots of starch were employed as the carbon source of the cultivation for the economical amylase production. 5.2 U/ml of amylase was obtained In the cultivation using 1 % (w/v) of food wastes. The amylase showed the highest activity at enzyme reaction conditions of 60$^{\circ}C$ and pH 4.5 and showed 90% of residual activity after the reaction at 50$^{\circ}C$ for 2 days. In the enzymatic hydrolysis reaction using 20% (w/v) of food wastes and 2.5 U/ml of amylase, 72.6 g/l of reducing sugar was obtained at the reaction condition of 50$^{\circ}C$, pH 4.5 for 2 days.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.441-445
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• 1987

The gene coding for alkaline amylase of alkalophilic Bacillus sp. AL-8 was cloned and expressed in Escherichia coli which was lack of amylase activity. For the cloning of the alkaline amylase gene, the chromosomal DNA and plasmid vector pBR322 were cleaved at the site of EcoRI and the gene was cloned. The selection of the transformants carrying the amylase gene was based on the their antibiotics resistance and amylase activity of the transformants. The recombinant plasmids pJW8 and pJW200 containing 5.8Kb and 3.0Kb EcoRI inserts respectively were proved to can the alkaline amylase gene. Alkaline amylase expressed in E. coli was characterized. The enzyme was proved to be stable at the range of alkaline pH.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.127-131
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• 1991

${\alpha}-amylase\;and\;{\beta}-amylase$ were extracted from barley and wheat malt, respectively. Their kinetic parameters on gultinous and nonglutinous rice starch were examined. During the germination of barley and wheat, the increaments of ATP levels were significant after 2-day germination and the levels were reduced after 5 days. The dry weights were decreased after 3 days. The activities of amylases were the highest for 6 days in the barley and wheat malt. As for ${\alpha}-amylase$, that the substrate affinity of barley malt on nonglutionous rice starch was greater than other cases. The $V_{max}$ values of ${\alpha}-amylase$ from wheat malt on either type of rice starch showed high, and from barley malt on nonglutinous rice starch were high. The ${\beta}-amylse$ from barley malt showed high substrate affinity on the glutinous rice starch, and $V_{max}$ value of the enzyme from wheat malt on glutinous rice starch was higher than other. The substrate efficiency ($V_{max}/K_{m}$) of ${\beta}-amylase$ on the non glutinous rice strach was better than other cases.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.763-767
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• 2005

Effect of ${\alpha}-amylase$ and various emulsifiers on characteristics of bread dough were examined. Fungal or bacterial ${\alpha}-amylase$ and various emulsifiers including monoglyceride (MG), sodium stearoyl-2-lactylate (SSL), and diacetyltartaric acid ester of mono- and diglycerides (DATEM) were added to bread dough both individually and as mixtures. Rheological characteristics of various bread doughs were examined through falling number, farinograph, alveograph, and rapid visco analysis. Results obtained showed falling number decreased via degradation of starch by ${\alpha}-amylase$. In farinogram, addition of ${\alpha}-amylase$ and emulsifiers in dough decreased consistency, water absorption, mechanical tolerance index, and dough development time. Farinogram characteristic was improved by adding SSL+MG to dough formula. Similar to farinogram addition of ${\alpha}-amylase$ and emulsifiers in alveogram of dough decreased overpressure, extensibility, swelling index, and deformation energy. Whereas addition of ${\alpha}-amylase$ did not affect pasting temperature, viscosity of dough tended to decrease.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.36-41
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• 2003

In order to increase the production and secretion rate of mouse salivary $\alpha$-amylase from Saccharomyces cerevisiae, various experiments were attempted. A plasmid pCNNinv (AMY) was constructed by the substitution of ADCl promoter and native signal sequence of mouse salivary $\alpha$-amylase cDNA gene with PRBI promoter and yeast invertase leader sequence, which resulted in 25% increase in the production of $\alpha$-amylase in the culture medium. The respiratory deficient transformant carrying pCNNinv (AMY) were obtained by treating yeast cells with ethidium bromide, and the $\alpha$-amylase activities in the culture brothes of the respiratory-deficient transformants were 5-8 times higher than that of parental wild type strain. $\alpha$-Amylase activity was also increased 3 times when the 0.015% (w/v) of 2-mercaptoethanol was added to the culture medium.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1390-1401
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• 2023

In this study, a 12-week feeding experiment was conducted to characterize the effects of exogenous α-amylase on the growth, feed utilization, digestibility, plasma α-amylase activity, feed degradation rate, and fecal particle size of olive flounder (Paralichthys olivaceus). Diet was supplemented with 0 (AA₀; control), 100 (AA₁₀₀), 200 (AA₂₀₀), or 400 (AA₄₀₀) mg/kg of α-amylase, respectively. Fish (273.1 ± 2.3 g) were stocked into 12 tanks (25 fish/1,000-L tank) and 3 tanks were randomly selected for each diet group. As a result, α-amylase was found to have no significant effects (p ≥ 0.05) on the growth, feed utilization parameters, and whole-body proximate compositions. α-Amylase-treated fish exhibited only a significant increase in the apparent digestibility coefficient of carbohydrates compared to the controls. In addition, in vitro analyses revealed that α-amylase dose-dependently increased (p < 0.05) the feed degradation rate, while photographs of the intestinal content after 2, 4, and 8 h of feeding demonstrated an improved degradation rate in the α-amylase-treated groups. Plasma α-amylase content was higher in the AA₂₀₀ and AA₄₀₀ groups, whereas the control group produced significantly larger-sized fecal particles (90% size class) than these two groups. In the intestine, no changes were observed in the expression levels of the immune-related TNF-α, IL-1β, IL-2, immunoglobulin-M, HSP-70, lysozyme, and amylase alpha-2A. However, growth-related genes IGF-1, IGF-2, TGF-β3, and growth hormone genes were upregulated in muscle tissues. Collectively, exogenous α-amylase has positive roles in the modulation of the digestibility coefficient, blood α-amylase concentration, growth-related gene expression, and diet degradation for improved digestion in olive flounder.

• Journal of Plant Biology
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• v.34 no.2
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• pp.159-163
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• 1991

The effect of dimethipin, one of the synthesized plant growth regulators, on the gibberellic acid-induced a-amylase activity in the barley de-embryonated seed system was investigated in order to elucidate the possible action mechanism of dimethipin. Dimethipin markedly inhibited the increase of mRNA and protein content, and a-amylase activity induced by gibberellic acid. The inhibitory effects were gradually decreased as the time interval between gibberellic acid treatment and dimethipin addition was made larger. Dimethipin inhibited the increase of mRNA content when added within 18 h from gibberellic acid treatment; however, it inhibited the increase of soluble protein content and a-amylase activity even added after 18 h from the treatment. These results suggest the possibility that dimethipin inhibit both mRNA synthesis and a-amylase protein synthesis.thesis.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.103-108
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• 1978

Acid-stable ${\alpha}-amylase$ was partially purified from Paecilomyces subglobosum by Sephadex G-150 gel filtration. About 7.7-fold purification was obtained and the partially purified preparation has 5.0 U of ${\alpha}-amylase$ activity per mg of protein. Using this partially purified ${\alpha}-amylase$, general properties were studied and it showed the maximal activities at the conditions of pH 4.0 and $38^{\circ}C$. High stability of the acid-stable ${\alpha}-amylase$ in acidic condition was observed, whereas thermal stability was similar to the conventional ${\alpha}-amylase$.