• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.237-239
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• 1985

The effects of red light on the $\alpha$-amylase activity of barley during germination was studied. The $\alpha$-amylase activity was highest at 5th day on germination, showing rapid increase from the 3rd-day of germination. The highest activity of $\alpha$-amylase was shown among the groups treated by red light at 100 Lux luminous intensity for 3 hours a day. The $\alpha$-amylase activity of barley during germination under the red light increased to 44% compared with that of barley during germination under the dark. The protein content was not increased by red light.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.591-595
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• 1990

A promoting effect of ginseng saponin on the growth recovery rate of Saccharomyces rouxii which was treated by heat was confirmed in previous report(22). In order to deduce the promoting effect on the growth recovery of the heat stressed yeast, the effect of ginseng saponin on the activity and the heat stability of the amylase produced by Sacchirromyces rouxii were observed. The amylase showed the highst activity at 0.01％ of saponin. At this concentration, the activity increased about 23％ compared to the control. Furthermore, the ginseng saponin showed a protective effect against thermal inactivation of the amylase produced by Saccharomyces rouxii.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.166-173
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• 1992

The expression of Bacillus subtilis $\alpha$-amylase from the phoA-amyE fusion gene in recombinant E. coli was investigated under various environmental conditions. The overexpression of cloned $\alpha$-amylase caused retardations in cell growth and synthesis of alkaline phosphatase (AP) from the chromosomal phoA gene. The change of culture temperature from $37^\circ{C}$ to $30^\circ{C}$ increased the specific activities of both $\alpha$-amylase and $\beta$-lactamase by six and two times, respectively, whereas the AP activity remained unchanged. The experiments with chlorampenicol (a translation inhibitor) suggested the enhancement of $\alpha$-amylase activity at $30^\circ{C}$, and this was partly due to the stability of $\alpha$-amylase itself. The further decrease of the temperature to $25^\circ{C}$ slowed down both the cell growth and cloned-gene expression rate. The $\alpha$-amylase activity showed a maximum at pH of 7.4 while alkaline phosphatase was most effectively produced at pH of 8.3.

• Korean Journal of Microbiology
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• v.11 no.2
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• pp.89-100
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• 1973

Dextrinogenic and saccharogenic amylase activities of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their amylase activities are surveyed from taxnomical, ecological, and physiological viewpoints. Among the 151 strains of Rhizopus, strain number 49 exhibiting most prominent saccharogenic amylase activity is selected as a best strain, and strain number 17 is selected as a best strain for dextrinogenic amylase activity. Amylase activities of Rhizopus are so variable in different strains even in the same species. In general, however, R. japonicus, R. liquefaciens, and R. shanghaiensis show high saccharogenic amylase activities, and R.chiuniang, R.achlamydosporus, and R.bahrnensis show high dextrinogenic amylase activities, while R.nigricans exhibits lower activities for both amylase. The strains isolated from kneaded cereals, such as "meju" and "kockja", exhibited very strong dextrinogenic and saccharogenic amylase activities as compared with the strains isolated from other sunstrates. The mean value of dextrinogenic amylase activities of the strains from southern inland region and saccharogenic amylase activities of the strains from middle coast region are, more or less, higher than those of the strains from the other regions. In the culture at 30.deg.C, those strains which exhibit better mycelial and air mycelial growth than sporangial formation show very high dextrinogenic and saccharogenic amylase activities. amylase activities.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.1-3
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• 2015

This study investigated the inhibitory activities of 2-hydroxyquinoline and its analogs against ${\alpha}$-glucosidase and ${\alpha}$-amylase. Based on the $IC_{50}$ values of 2-hydroxyquinoline analogs tested against ${\alpha}$-glucosidase and ${\alpha}$-amylase, 2-hydroxyquinoline had potent inhibitory activity (64.4 and $130.5{\mu}g/mL$, respectively), while 2-methyl-8-hydroxyquinoline showed weakly inhibitory activity (90.7 and $215.4{\mu}g/mL$, respectively). 2-Methylquinoline demonstrated no activity against ${\alpha}$-glucosidase and ${\alpha}$-amylase. In conclusion, 2-hydroxyquinoline analogs, with the existence of a methyl group and hydroxyl on quinoline, can be useful as a new diabetes treatment.

• The Korean Journal of Food And Nutrition
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• v.8 no.1
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• pp.32-36
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• 1995

Changes in the w-amylase activity and free sugar contents were Investigated during buckwheat (Fagopyrum esculentum Moench) germination at 1$0^{\circ}C$ for 7 days. The a-amylase activity in ungerminated seeds was 1.66 U. It increased for the 1st day of germination, but then decreased until 3rd day, and thereafter Increased. The free sugar contents In ungerminated seeds were as follows. The maltose, fructose, glucose and rhamnose were 1.81mg%, 0.42mg%, 7.71mg%, 6.80mg% on dry weight basis, respectively. The maltose and fructose contents decreased in the initial stage of germination, but then gradually increased. The glucose contents decreased for the 3rd day, but sharply Increased afterwords. The rhamnose contents decreased until 1 day, and then there was no significant change for the 6 days.

• 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.

• Journal of Microbiology and Biotechnology
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• v.7 no.5
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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.

• Food Science and Preservation
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• v.21 no.2
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• pp.286-293
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• 2014

In this study, one GRAS strain was screened from doenjang, a traditional Korean fermented food, as a microorganism producing amylase due to the formation of a clear zone on the medium including soluble starch. From the analysis of the gene sequence of 16S ribosomal RNA, the strain was identified as Bacillus subtilis and was therefore named Bacillus subtilis CBD2. When the nutrient broth medium was prepared with 3% NaCl, 5% glucose, and the initial medium pH 7.0, the B. subtilis CBD2 showed maximum growth. Among soluble starch, corn starch, maize amylopectin, and wheat starch, soluble starch was the most effective carbon source in the production of amylase by B. subtilis CBD2. The amylase from B. subtilis CBD2 showed the highest activities at pH 8.0 and $50^{\circ}C$, and corn starch was the most proper substrate for the enzyme activity. When corn starch was used as a substrate, the production of sugars through enzyme activity increased for 24 h, and then the enzyme activity became constant.

• Journal of Aquaculture
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• v.18 no.4
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• pp.245-251
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• 2005

This study was investigated the condition of their maximum activity to assay the enzymes of rotifer, Brachionus rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin and TG-lipase activities of rotifer were higher and more sensitive in phosphate-NaOH buffer than Tris-HCl buffer. $\alpha$-amylase, trypsin and TG-lipase activities were appeared the maximum at pH 8.0, and total alkaline protease activity showed the maximum activity at pH 7.0. $\alpha$-amylase activity showed the highest activity at $40^{\circ}C$, and total alkaline protease and trypsin activities were assayed the highest at $55{\~}60^{\circ}C$. However, TG-lipase activity was appeared the highest at $25{\~}30^{\circ}C$. The optimum substrate concentration of enzyme activity of a-amylase, total alkaline protease, rypsin and TG-lipase were $3.5\%$ starch, $\0.6%$ azo-casein, $87.5{\mu}M$ BApNA and 81.2 mM olive oil, respectively. The optimum reaction time of enzyme activity of $\alpha$-amylase, total alkaline protease, trypsin and TG-lipase were increased up to 40, 60, 30 and 25 min., respectively. The data obtained in this study could be used for the digestive enzyme research of rotifer, B. rotundiformis.