• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.203-207
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• 1999

V. alginolyticus 138-2, a marine halophilic bacterium, produced an extracellular amylase with a molecular weight of ca. 56,000. The analysis of the digestion products of soluble starch by thin layer chromatography(TLC) revealed that the extracellular amylase of V. alginolyticus 138-2 is a saccharifying-type alpha-amylase. The alpha-amylase activity of the culture supernatant of soluble starch was optimal at pH 6.0 and 45$^{\circ}C$. Ca2+ slightly increased the alpha-amylase activity, whereas Hg2+, An2+, Cu2+, Ni2+, Fe2+, and Mn2+inhibited the enzymatic activity. Alkylating thiol group agent, iodoacetic acid did not affect the alpha-amylase activity, but reduced thiol reagents such as dithiothreitol, cysteine, and beta-mercaptoethanol stimulated theenzymatic activity. On the other hand, even if V. alginolyticus 138-2 is a marine halophilic bacterium, its alpha-amylase activity was significantly inhibited by NaCl.

• Journal of Sericultural and Entomological Science
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• v.24 no.2
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• pp.73-80
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• 1983

1. The varietal difference in amylase activity of the digestive fluid of the 5th instar larvae reared on the artificial diet was investigated, using the parent commercial silkworm varieties of Japanese strain. The amylase activity was large different among silkworm varieties. The activity was strong in Hansaeng-1, Jam 115 and Jam 117, medium in Hansaeng-3, Jam 113, Jam 119, and Jam 201, weak in Jam 107, Jam 121 and Gyeongchu. The amylase of the digestive fluid of ten parent commercial silkworm varieties is possible-(ae) type, compared with ＋(＋$\^$ae/) type of Daizo. 2. To investigate the effect of a-amylase pre-treatment of the artificial diet, larvae were fed with the diet treated by a-amylase during 4th-5th instar periods. The blood sugar content and cocoon qualities were slightly higher in the experimental larvae than those in the control, while showing the slight less body weight, amylase activity and dietary efficient.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.35-38
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• 1959

The enzymatic activity of amylase which was isolated from a shell fish Veneridae Soxidmnus purpuratus Sowerby(Korean name :Gai-jo-gai") was studied and the obtained results were as follows: (1) The optimum pH of the enzyme was Ca. 6.2-6.4. (2) Prohibiting activity of metalic ions for the enzymatic activity was the order of 1/1000M-$Mg^{++}$>1/1000M-$Sr^{++}$>1/1000M-$Na^{+}$, and $Ca^{++}$ ion's prohibiting action was hardly showed. (3) Of 3 specimens of amyiase from Heptapancreas, Gastro-intestine and crystalline style, the highest activity was shown by amylase from crystlline style, and the other two showed almost same degree of activity. (4) Heptapancreas Amylase from the shell fish showed remarkably higher enzymatic activity than the pancreas amylase from a pig.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1749-1754
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• 2006

Two slaughter experiments were conducted to determine the effects of rumen escape starch, by altering dietary starch concentration and corn particle size, on ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta of lambs. In experiment 1, 18 wether lambs (28.5${\pm}$1.6 kg) were fed low, medium or high starch diets for 35 d and slaughtered. Dietary starch concentrations linearly increased rumen escape starch (p<0.05). Pancreatic ${\alpha}$-amylase activity was lower (p<0.05) in lambs fed the low starch diet. When expressed per gram of digesta, ${\alpha}$-amylase activity was lower in lambs fed the low starch diet. However, expressed as total activity, ${\alpha}$-amylase in the digesta was greater in lambs fed the medium starch diet. In experiment 2, 12 wether lambs (23.5${\pm}$0.3 kg) were fed diets with finely cracked corn, coarsely cracked corn and whole corn. These dietary treatments continued for 35 d before tissue collection. Rumen escape starch increased with increasing corn particle size (p<0.05). ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta was significantly greater (p<0.05) in lambs fed the coarsely cracked corn. These data suggest that increasing rumen escape starch results in a quadratic increase in total ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta. Maximum ${\alpha}$-amylase activity is reached when rumen escape starch is about 100-120 g/d in 25-30 kg lambs.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1421-1426
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• 1999

Sixteen domestic barley varieties and subsequently produced malts were evaluated for quality characteristics. Diastatic power(DP), complementary actions of amylases in malt, had a wide $variation(139{\sim}220^{\circ}L)$ among the barley varieties. Some 6-row barley varieties demonstrated significantly high DP values. ${\beta}-\;and\;{\alpha}-amylase$ activities in malts were also significantly influenced by barley varieties. Diastatic power was highly correlated with ${\beta}-amylase$ activity, indicating that the ${\beta}-amylase$ activity was a predominant factor determining saccharifying action in malt. Amylograph was used to indirectly estimate starch-degrading enzymatic activity, and the reduction in amylograph viscosity was associated with ${\alpha}-amylase$ activity. Barley quality factors in relation to enzymatic activity of malt were analyzed, and the barley variety with lower kernel weight and less plumper kernels tended to produce higher starch-degrading enzyme activity. Potential diastatic power, an estimate of bound ${\beta}-amylase$ in raw barley, was associated with diastatic power in the final malt. Potential diastatic power turned out to be an important factor for predicting good malting barley.

• Korean Journal of Microbiology
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• v.15 no.1
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• pp.31-41
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• 1977

Dextrinogenic and glucoamylase activities of Aspergillus isolated from various habitat-substrates collected through South Korea are measured, and their amylase activities are surveyed in taxonomical and ecological viewpoints. 1. A. flavous group and A.wentii group exhibited higher activities for both amylases than others. 2. In the relations between amylase activity of Asperguillus and their habitat-sub-strates, the strains isolated from meju and cereals exhibited predominant dextrinogenic amylase activity. 3. Dextrinogenic amylase activity of Aspergillus is higher in the strains isolated from southern coast than the other regions. 4. Among the 601 strains of Aspergillus surveryed, strain No.74 and strain No.421 exhibited the most predominant activity for dextrinogenic amylase and glucoamylase, respectively.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.159-168
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• 1998

Effect of plant growth regulators and end-product on the enzyme activities in cotyledons of Vigna angularis during germination was investigated by measuring the changes of $\alpha-amylase$ activities in attached and detached cotyledons applied growth regulators and sugars. The higher levels of $\alpha-amylase$ in detached cotyledons than those in cotyledons attached to the embryonic axis were due to both faster synthesis and slower degradation of the enzyme in the detached cotyledons than in the attached cotyledons. Levels of $\alpha-amylase$ activity were reduced by high concentrations of glucose and sucrose, and it is suggested that this effect was caused mostly by osmotic stress and partly by end-product repression. In detached cotyledons exogenously supplied $GA_3,$ IAA, kinetin, or their combinations has a small promotive effect on the developmental patterns of $\alpha-amylase$ activity ABA and uniconazole both prevented the synthesis of $\alpha-amylase$. Glucose inhibition of enzyme activity was partly reversed by the application of $GA_3,$ and CAMP. $GA_3,$ and cAMP seemed to act through a similar mechanism. The addition of inhibitors of protein and RNA synthesis largely prevented the increase of enzyme activity in the presence or absence of exogenous $GA_3,$. The pretreatment experiments with canavanine indicated that the earlier the time of addition was, the lower the amylase activity was.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1164-1173
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• 2006

Cellulase from Aspergillus niger, (${\alpha}$-amylase from Bacillus sp. and protease from Bacillus globigii were used as enzyme sources in this study to examine how their respective substrates protect them in two kinds of simulated gastrointestinal tract digesting processes. Avian total digest tract simulation test showed that filter paper, Avicel and cellulose resulted in 7.7, 6.4 and 7.4 times more activity than of unprotected cellulose, respectively. Protease with addition of casein, gelatin or soybean protein showed no significant protection response. Starch protected amylase to be 2.5 times activity of the unprotected one. Monogastric animal total tract digestion simulation test showed that filter paper, Avicel and cellulose resulted in 5.9, 9.0 and 8.8 times activity of unprotected cellulase, respectively. Casein, gelatin and soybean protein resulted in 1.2, 1.3 and 2.0 times activity of unprotected protease, respectively. Starch did not protect amylase activity in monogastric animal total tract simulation. Protection of mixed enzymes by substrates in two animal total tract simulation tests showed that filter paper in combination with soybean protein resulted in 1.5 times activity of unprotected cellulose, but all substrates tested showed no significant protection effect to protease. Soybean protein and starch added at the same time protected the amylase activity to be two times of the unprotected one. Test of non-purified substrate protection in two animal total digest tract simulation showed that cellulase activity increased as BSA (bovine serum albumin) concentration increased, with the highest activity to be 1.3 times of unprotected enzyme. However, BSA showed no significant protection effect to protease. Amylase activity increased to 1.5 times as BSA added more than 1.5% (w/v). Cellulase activity increased to 1.5 times as soybean hull was added higher than 1.5%. Amylase had a significant protection response only when soybean hull added up to 2%. Protease activity was not protected by soybean hull to any significant extent.

• 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.