• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.26-30
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• 1993

Strain of treptomyces minoensis DMCJ-144 was tried to be improved so that it produces much more the $\alpha$-amylase inhibitor. Streptomyces minoensis DMCJ-144 was treated with 1 mg/mι (pH 9.0) of N-methyl-N'-nitro-N-nitrosoguanidine at $30^{\circ}C$ for 60 min and irradiated with UV light distanced 30 cm for 20 min. After mutagenesis, surviving colonies were cultured on the CM contaning acriflavine ($10{\mu}g/ml$) three times in order to enhance the mutability. And then through multi-level screening, colonies that ${\alpha}$-amylase inhibitor productibility. was Improved were selected by modified-blue value method. After third acriflavine treatment, $\alpha$-amylase inhibitory activities of selected colonies were found to be much better as compared with that of parent strain. One mutant strain showed 5.4 time inhibitory activity than the parent strain.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.189-193
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• 2005

Effect of enzyme treatment on physicochemical characteristics of small tea bean percolate were estimated. Three types of small red bean percolate were prepared by heat treatment for 30 min at $95^{\circ}C$ (1st), 30 min at $95^{\circ}C$ (2nd), and 40 min at $120^{\circ}C$ (3rd). They were then treated with 0.5% ${\alpha}-amylase$ (v/v) for 4 hr at $108^{\circ}C$ (${\alpha}-amylase$ treatment), then with 0.5% ${\beta}-amylase$ (v/v) for 4 hr at $60^{\circ}C$ (${\alpha}-$ and ${\beta}-amylase$ treatment). Crude saponin contents of 1st-3rd percolates were 0.82, 1.44, and 1.52 mg/g, respectively. ${\circ}Brix$ of small red bean percolates treated with enzymes increased to $0.8-1.2\;{\circ}Brix$ with 2nd and 3rd percolates showing no significant difference between ${\alpha}-amylase$ and ${\alpha}-$ and ${\beta}-amylase$ treatments. pH of 3rd percolate treated with ${\alpha}-$ and ${\beta}-amylase$ decreased from initial 6.2 to 4.7. Hunter L value of small red bean percolate treated with ${\alpha}-$ and ${\beta}-$ decreased, whereas a and b values increased. Small red bean beverage made with 3rd percolate showed high score in flavor, taste, and overall acceptability. Results suggest small red bean percolate treated with enzymes could be used for preparation of small red bean beverage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.108-111
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• 2000

Osmoconditioning and hardening effects for the seed germination of normal and naturally aged rice seeds were studied through analyzing the total sugars and $\alpha$-amylase activity. The normal seeds which used to have high germination rate accelerated germination with the osmoconditioning at the suboptimal temperature of 17$^{\circ}C$. On the other hand, the aged seeds did not affect germination rate at $25^{\circ}C$, while increased germination rate and accelerated germination a little at 17$^{\circ}C$, Hardening of aged seeds increased germination rate by 10-15% compared with control seeds at both 17 and $25^{\circ}C$ and accelerated germination. Total sugar content and $\alpha$-amylase activity of normal seeds were higher than did aged seeds. The aged seeds with treatment of osmoconditioning and hardening increased total sugar content and $\alpha$--amylase activity, but hardening was more effective than osmoconditioning. The $\alpha$--amylase activity was positively correlated with the total sugar content and germination rate.

• The Korean Journal of Mycology
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• v.17 no.3
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• pp.149-153
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• 1989

One strain of Aspergillus niger K-25 producing an acid-stable ${\alpha}-amylase$ was isolated from the soil. The optimum culture conditions were investigated. The production of the acid-stable ${\alpha}-amylase$ was enhanced when the strain was incubated in a medium containing soluble starch 3.5%, peptone 2%, $KH_2PO_4$ 0.5%, $MaSO_4{\cdot}7H_2O$ 0.25% and $FeCI_3$ 1.0% at pH 3 for 7 days. However, higher activity of acid-stable ${\alpha}-amylase$ was demonstrated on wheat bran culture. Amylase production was doubled when A. niger K-25 was incubated on the wheat bran supplemented with fumaric acid buffer (pH 3).

• YAKHAK HOEJI
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• v.35 no.1
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• pp.30-37
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• 1991

Streptomyces actuosus DMCJ-49 and Streptomyces minoensis DMCJ-144 produce the .alpha.-amylase inhibitor. Inerspecific protoplast fusion technique was used to increase the productivity of .alpha.-amylase inhibitor. Four auxotrophic mutants were obtained respectively from two strains by N-methyl-N'-nitor-N-nitrosoguanidine(3mg/ml) treatment. The optimum conditions for the protoplast formation of Streptomyces actuosus DMCJ-49 ade was as follows; 1.2% w/v of glycine, 3mg/ml of lysozyme, and 30 min of lysozyme treatment followed by 36 hr. incubation in the protop-last formation medium. In case of DMCJ-144-his those were 1.2%w/v, 3 mg/ml, 30 minutes and 60 hours, respectively. Regeneration was accomplished with hypertonic soft agar medium that contained 0.4M sucrose, 20mM CaCl$_2$, 50 mM MgCl$_2$ and low levels of phosphate. Fusion of protoplasts carrying different auxotrophic markers was achieved by treatment with polyethylene glycol. The optimum concentration of polyethylene glycol 1450 for the production of recombinants was 40%w/v. When the protoplasts was treated with 40% polyethylene glycol for 30 minutes, the frequency of recombinants was 6.5$\times$$10^{-3}$ and the $\alpha$-amylase inhibition activity of $ade^-his^-$ No. 4, which is the fusant with the most improved activity increased from 33 to 125 I.U./ml.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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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.

• Journal of environmental and Sanitary engineering
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• v.23 no.1
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• pp.25-31
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• 2008

A bacterial strain, Bacillus megaterium L-49 has been isolated and identified that produces alkaline ${\alpha}$-amylase. The cell is ellipsoidal, about $1.0-1.2{\times}3.0-3.6{\mu}m$ in diameter, Gram-positive, motile, and central partial central. Growth occurs in media containing 7% of NaCl. This strain could utilize D-glucose, lactose, xylose, sucrose, mannose, and maltose, and but it does not utilize D-fructose, and glycogen. Among the various concentrations of saturated ammonium sulfate, the retractation ratio in range of 70 to 100% was about 93%. However, in the case of acetone, it was about 98.7%. EDTA has activating effect and Ca2+ has no effect on alkaline ${\alpha}$-amylase activity. The alkaline ${\alpha}$-amylase has low thermal stability. The optimal temperature for reaction is $50^{\circ}C$. The alkaline ${\alpha}$-amylase activity maintained stabilizing at pH 6-11 and the optimal pH for reaction was 9-10.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.149-156
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• 2014

Termites are wood pests that cause vast economic damage every year. They digest both cellulose and starch, but the enzymes for starch digestion have not been well characterized. We obtained complete amino acid sequence information on the KME1 ${\alpha}$-amylase from Reticulitermes speratus KMT1 through analysis of total mRNA sequences. The KME1 enzyme has two ${\alpha}$-amylase domains and is 68% identical to the ${\alpha}$-amylase from Blattellager manica, its closest relative in the GenBank database. Some unique features of its conserved region and its distant evolutionary relationship to other insect ${\alpha}$-amylases suggest that KME1 is a new type of ${\alpha}$-amylase.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.403-408
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• 1985

Enhancement of surfactant on release of secretory enzyme, such as $\alpha$-amylase, acid phosphatase and alkaline phosphatase, was investigated during submerged culture of Rhizopus oryzae. Morphological changes of colony was occured; small pelletal form in 0.18mM of sodium dodecyl sulfate, pulpy form in 0.48mM of sodium deoxycholate, and filamentous form in absence of surfactant. It. Supplement of sodium dodecyl sulfate induced 9 times increasing activity of $\alpha$-amylase and that of acid phosphatase 25 times in cultural fluids. Alkaline phosphatase was increased 11 times in cultural fluid and also stimulated in cytoplasm with supplement of sodium deoxycholate.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.352-359
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• 1990

The synergistic effect of glucoamylase and a -amylase on the hydrolysis of raw corn starch in an agitated bead reaction system was studied by investigating the changes of sugar profiles, the granular structure, particle size distribution, and X-ray diffraction pattern of residual raw corn starch. The enzymatic hydrolysis of raw corn starch was greatly enhanced by synergistic effect of glucoamylase and $\alpha$ -amylase. Even though the sugar profiles were mainly determined by the mixing ratio of glucoamylase and $\alpha$-amylase; raw starch was mainly converted to glucose directly without accumulation of any significant amount of oligosaccharides. The cavity formation and fragmentation phenomena of raw corn starch granule subjected to enzyme reaction were analyzed by means of SEM and the particle size distribution. The X-ray diffraction pattern of raw starch was not changed at the initial stage of reaction but slightly changed at the late stage of hydrolysis, which may be caused by the preferential degradation of amorphous region by enzymatic reaction, not by the destruction of microcrystalline structure of raw corn starch.