• Applied Biological Chemistry
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• v.29 no.3
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• pp.248-254
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• 1986

The product specificity of Bacillus ${\alpha}-amylase$ on raw rice starch has teen studied by using HPLC and scanning electron microscopy (SEM). Analysis of starch degradation products digested by ${\alpha}-amylase$ showed considerable differences between raw and gelatinized rice. The hydrolysis of raw rice starch resulted in formation of more glucose and maltose than those of gelatinized starch. SEM revealed characteristic enzyme degradation patterns. Hollow curvatures were observed in gelatinized starch, indicating the substrate is hydrolyzed in the interior of the starch chain by Bacillus ${\alpha}-amylase$. In contrast, raw starch were hydrolyzed from the end of the substrate, resulting in pinholes over the surface of the starch granules.

• Restorative Dentistry and Endodontics
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• v.38 no.3
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• pp.141-145
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• 2013

Objectives: Assessment of dental pain severity is very challenging in dentistry. Previous studies have suggested that elevated salivary alpha amylase may contribute to increased physical stresses. There is a close association between salivary alpha amylase and plasma norepinephrine under stressful physical conditions. The aim of this study was to evaluate the relationship between pain severity and salivary alpha amylase levels in patients with symptomatic irreversible pulpitis. Materials and Methods: Thirty-six patients (20 females and 16 males) with severe tooth pain due to symptomatic irreversible pulpitis were selected. The visual analogue scale (VAS) score was used to assess the pain severity in each patient. Unstimulated whole saliva was collected, and the level of alpha amylase activity was assessed by the spectrophotometric method. Statistical analysis was performed using SPSS 13. Results: The level of alpha amylase was significantly increased in the saliva in association with pain severity assessed by VAS. The salivary alpha amylase was also elevated with increased age and in males. Conclusions: There was a significant correlation between the VAS pain scale and salivary alpha amylase level, which indicates this biomarker may be a good index for the objective assessment of pain intensity.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.293-296
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• 1996

The present study was carried out to investigate the effect of Ni on germination, cell elongation, ${\alpha}-amylase$ activity, contents of chlorophyll and protein in radish were determined in the water culture. As the concentration of Ni was increased in the water culture, germination of radish was 55% by Ni 10 mg/kg and 30% by Ni 20 mg/kg. The ratio of cell elongation injury was 50%, by two days after Ni 20 mg/kg treatment. The injury ratio of ${\alpha}-amylase$ activity was 45% in the same condition and as the time goes on, inhibition of ${\alpha}-amylase$ activity were slightly decreased. Contents of chlorophyll a and b were decreased two days after treatment and chlorophyll a was more inhibited than chlorophyll b. Also changes of the protein contents was slightly decreased. Activity of ${\alpha}-amylase$ was decreased at germination stage, contents of chlorophyll a and b were decreased at growing stage.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.32-38
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• 2005

Effects of acid and ${\alpha}$-amylase on resistant starches including retrograded RS3 and cross-linked RS4 prepared from normal maize starch were investigated. Acid and ${\alpha}$-amylase hydrolytic patterns of RS3 were similar, while those of native starch and RS4 differed. Acid hydrolysis rate of RS3 was markedly higher at initial stage, then slowly decreased up to 20 days, whereas that of RS4 increased continuously. The sizes of acid- and ${\alpha}$-amylase-treated RS3 residues decreased, but those of RS4 remained unchanged. X-ray patterns of all treated residues did not change; however, the peak intensities increased. Swelling power of RS3 increased to 150% at $95^{\circ}C$, whereas that of RS4 differed depending on the treatment condition. Swelling power of acid-treated RS4 residue increased markedly, but that of ${\alpha}$-amylase-treated one remained constant. Gel filtration chromatography profiles of untreated RS3 and RS4 residues were similar, whereas that of acid-treated RS4 residue was different from them. RS showed different hydrolytic behavior by acid and ${\alpha}$-amylase depending on the type, and susceptibility of RS3 was higher than that of RS4.

• Microbiology and Biotechnology Letters
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• v.3 no.2
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• pp.73-82
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• 1975

In the course of studies on the production of thermostable amylases by thermophilic actinomycetes isolated from soils the investigation was carried out on the production of $\alpha$-amylase by G-1011 strain which had presented the most remarkable $\alpha$-amylase formation ability among 128 amylolytic isolates. The results were as follows ： 1. Characteristics of G-1011 strain were compared with those descriptions of thermophilic actinomycetes given in Bergey's Manual. The strain was identical to these species of actinomycetes. The details of physiological properties of the strain luould he published in near future. 2. The optimum temperature for incubation of the cell growth of G-1011 strain and $\alpha$-amylase production by the strain was revealed to 5$0^{\circ}C$. 3. The effective medium for $\alpha$-amylase formation by the strain was consisted of 3.0%, soluble starch, 1.0%, peptone, 0.5%, yeast extract, 0.5%, NaCl, 0.1%, MgSO$_4$ㆍ7$H_2O$ 0.02%, $K_2$MPO$_4$and 0.002% FeSO$_4$ㆍ7$H_2O$. The pH of the medium was ajusted to 7.0 with phosphate buffer solution. 4. The maximum production of $\alpha$-amylase (3420 D. U/ml) by G-1011 strain resulted when it was grown for 16 hours with the culture of reciprocal shaking.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.358-362
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• 1988

Aqueous two-phase fermentation system was tested for the overproduction of extracellular enzyme through $\alpha$-amylase fermentation by Bacillus amyloliquefaciens. By employing aqueous two-phase system $\alpha$-amylase activity showed 25% increase compared to the result using regular medium and no deactivation of the enzyme was observed. The presence of polyethylene glycol was observed to promote the enzyme production, while to inhibit the growth of the microorganism. It is recommended that polyethylene glycol be added during the log-growth phase and dextran be added after the enzyme activity reaches Its maximum for efficient $\alpha$-amylase fermentation and in situ recovery of the enzyme.

• The Korean Journal of Mycology
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• v.13 no.4
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• pp.203-212
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• 1985

Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ${\alpha}-amylase$ and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of $1{\sim}13$ and at $100^{\circ}C$ for half an hour, also inhibited other amylases such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and glucoamylase. However, it showed no inhibitory activity against ${\alpha}-glucosidase$, ${\beta}-glucosidase$, dextranase, and ${\beta}-amylase$. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ${\alpha}-amylase$ were noncompetitive.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.277-283
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• 2017

To produce sweet liquor without artificial sweeteners, 8 traditional rice pre-treatment methods (juk, beombeok, seolgitteok, gumeongtteok, mulsongpyeon, injeolmi, gaetteok, and godubap) were analyzed in this study. The formation of sugars with the help of ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase using nuruk as a substrate has been previously confirmed. During the early stages of the pre-treatment processes, the amount of maltose produced (in descending order of its concentration) by ${\alpha}$-amylase was observed to be as follows: gaetteok > seolgitteok > beombeok > mulsongpyeon > juk > injeolmi > gumeongtteok > godubap. However, changes in maltose concentrations with respect to the pre-treatment processes after 48 hours were observed to be as follows: injeolmi > beombeok = godubap > gumeongtteok > gaetteok = mulsongpyeon > seolgitteok > juk. Maltose produced using either ${\alpha}$-amylase or ${\beta}$-amylase showed similar results. Glucoamylase produced 10 mg/ml of glucose during the godubap process, which was the highest amount of glucose among all the methods. Moreover, when ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase were used concurrently, glucoamylase increased glucose production in the later stages. Therefore, the possibility of producing sweet liquor without employing artificial sweeteners was confirmed, even if the amount of sugar in the liquor varied with the pre-treatment process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.275-282
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• 1993

The objective of this study was to clone a partial fragment of $\alpha$-amylase from Korean maize. We designed and synthesized an oligonucleotide probe and two kinds of PCR primers based on cDNA conserved region of $\alpha$-amylase sequences from other plants. Total RNA from 3-day-old maize seedling was used as template for 1st strand cDNA synthesis and RNA-DNA hybrid was used as template for polymerase chain reaction(PCR). The product of PCR was about 0.5 kb long and inserted into pUC19. We named this recombinant plasmid as pZM$\alpha$'. The cloned fragment was certified by Southern blot analysis using labeled synthetic oligonucleotide as probe.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.412-420
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• 1989

To know how the ribosomes involved in secretory protein synthesis were attached to the cytoplasmic membrane in Bacillus amyloliquefaciens, the cells were treated with puromycin combinated with magnesium at the logarithmic phase, and the variation of cell-bound and extracellular $\alpha$-amylase activity was assayed for determining the $\alpha$-amylase translocation blocking through the cytoplasmic membrane. In the abnormal $\alpha$-amylase producing mutant in which the C-terminal of the $\alpha$-amylase structure was deleted, B. umytotiquefaciens CH10-2, the $\alpha$-amylase was translocated normally through the cytoplasmic membranes, and the translocation blocking by puromycin was revealed to have a similar pattern as that in the wild type. This means that the C-terminal part of the enzyme structure may not have a signal for secretion. The cell death of the logarithmic phase cells in both strains was not affected much under 20$\mu\textrm{g}$/$m\ell$ of puromycin, however, the $\alpha$-amylase translocation was blocked markedly under less than 10$\mu\textrm{g}$/$m\ell$ of the puromycin concentration. The blocking of the enzyme secretion by puromycin may be due to the detachment of the ribosomes from cytoplasmic membranes by disturbing the nascent polypeptide synthesis. Further evidence for confirming this was that the detachment was increased in 50 mM of magnesium ion because the extracellular $\alpha$-amylase activity was decreased more under this condition. If the cells were treated with trypsin combinated with Iysozyme, the extracellular $\alpha$-amylase activity from the cultured medium was reduced markedly, however, the activity from the cells treated with trypsin only was not reduced. This means that the nascent polypeptides protruding from the cytoplasmic membrane were sensitive to the trypsin digestion, whereas the matured ones were not. Therefore, the protruding polypeptides from the cytoplasmic membranes may be truncated by trypsin before forming their final tertiary structures by folding in the cell wall layer.