• Microbiology and Biotechnology Letters
• /
• v.14 no.3
• /
• pp.209-212
• /
• 1986

$\alpha$-Amylase gene of Bacillus amyloliquetaciens was cloned on plasmid YEp13, S. cerevisiae-E. coli shuttle vector. Hybrid plasmid pTG17, carrying $\alpha$-amylase gene of B. amyloliquefaciens, was transformed to E. coli and the expression of it in yeast was investigated. This plasmid was unstable in E. coli and produced two minor plasmids, pTG17-1 and PTG17-2, which resulted from the segregation of it. Transformant of S. cerevisiae MC16 with pTG17-1 plasmid was not appeared on SD medium because of the Leu2 gene defection. S. cerevisiae could be transformed by the hybrid plasmid, and $\alpha$-amylase activity of the yeast transformant was detected by somogyi-Nelson method and agar diffusion method.

• Food Science and Preservation
• /
• v.17 no.2
• /
• pp.290-296
• /
• 2010

To develop anti-acidosis and anti-diabetes agentsfrom natural products, the inhibitory activities of Brazilian plant extracts against microbial $\alpha$-amylase and $\alpha$-glucosidase were evaluated. Among 100 different ethanol extracts tested, those of Acacia jurema Mart., Anacardium humile A. St.-Hil., Cedrela odorata L., and Guazuma ulmifolia Lam showed good inhibitoryactivities toward both enzymes. In addition, an extract of Plumeria drastica Mart. showed specific inhibition of $\alpha$-amylase, whereas that of Eugenia uniflora L. demonstrated strong inhibition of the enzyme. IC50 values of $\alpha$-amylase inhibition suggested that the extract of A. humile A. St.-Hil., which has been used as an anti-diabetes medicine in Brazil, had potent inhibitory activity. The IC50 for the A. humile A. St.-Hil. extract ($91.2{\mu}g/mL$) was similar to that of acarbose ($50.5{\mu}g/mL$). This activity of A. humile A. St.-Hil. was not reduced by heat or acid treatment. Moreover, treatment with HCl (0.01 M) for 1 h increased the inhibitory activity from 57.5% to 81.2%. Also, the extract did not cause hemolysis of human red blood cells at levels up to 1 mg/mL. The results indicate that the extract of A. humile A. St.-Hil. is potentially useful as an anti-acidosis and anti-diabetes agent.

• Advances in Traditional Medicine
• /
• v.4 no.4
• /
• pp.227-234
• /
• 2004

An ${\alpha}-Amylase$ was purified to apparent homogeneity from germinating soybean seeds (Glycine max). Enzyme showed high specificity for starch. ${\alpha}-Amylase$ from soybean has optimum pH at 7.6 in the pH range 4.0-10.6. At this pH, the $K_m$ of starch was 2.63 mg/ml and the $V_{max}$ was equal to 52.6 mg/ml/min protein. Optimum temperature of the enzyme was found to be $55^{\circ}C,\;Q_{10}$ equal to 1.85 and energy of activation equal to 12 kcal/mol. Additives like, EDTA reduced the activity of ${\alpha}-amylase$ whereas PMSF enhanced the activity. ${\alpha}-Amylase$ was inhibited by several heavy metal ions.

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

• Journal of Microbiology and Biotechnology
• /
• v.4 no.3
• /
• pp.230-232
• /
• 1994

The enzymes $\alpha$-amylase and glucoamylase used in starch hydrolysis were found active in the supercritical carbon dioxide solvent Higher hydrolysis of starch sluny in supercritical $CO_2$ was achieved by operating the reactor for the first two hours with $\alpha$ -amylase and to subsequent addition of glucoamylase for continued hydrolysis.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1976.04a
• /
• pp.184.1-184
• /
• 1976

고온성방면균의 이용가능성을 검토할 목적으로 전보에서는 내열성 $\alpha-amylase$ 생산능이 극히 우수한 균주를 전국토양시료로 부터 분리하여 균주의 형태학적성질과 아울러 $\alpha-amylase$ 생산을 위한 배양조건을 검토하였으며 본보에서는 생산된 $\alpha-amylase의$ 효모학적 기본성질을 조사하여 그 결과를 보고코져 한다.

• Microbiology and Biotechnology Letters
• /
• v.47 no.3
• /
• pp.364-371
• /
• 2019

The use of GRAS microorganisms isolated from fermented foods during amylase production using an economical food-waste medium provides more opportunities to produce amylase with a wider range of applications. Hence, this study aimed to isolate a good amylase-producing fungi from the traditional Indonesian fermented cassava, gatot, and to identify the amylase-producing capability of the isolate in a potato peel waste (PPW) medium. Black-colored fungi isolated from gatot was morphologically identified and the amylase produced was characterized using SDS-PAGE and Native PAGE. The isolate was then grown on PPW medium, and the amylase produced was further characterized. Morphological identification and enzyme characterization revealed that the Aspergillus niger aggregate F isolated from gatot secreted an active extracellular ${\alpha}$-amylase with an optimum pH of 5-6. In conclusion, Aspergillus niger aggregate F isolated from gatot can be used to produce ${\alpha}$-amylase using PPW as a medium.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.2 no.2
• /
• pp.159-168
• /
• 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
• /
• v.50 no.3
• /
• pp.204-209
• /
• 2007

The objective of this research was to evaluate the inhibitory activities of phenolic compounds isolated from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$. The content of total phenolic compounds of water extract from Crataegi Fructus was 22.5 mg/g. The inhibitory activity of the water extract (200 ${\mu}g/ml$) from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was determined to be 100% and 82.6%, respectively. Isolation of inhibitory compounds was carried out on Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient elution procedure of increasing MeOH in $H_2O$. The chemical structure of the inhibitory compound against ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was confirmed as chlorogenic acid by spectroscopic analysis of FAB-MS, NMR and IR spectrum.

• Journal of Pharmaceutical Investigation
• /
• v.21 no.3
• /
• pp.143-147
• /
• 1991

${\alpha}-amylase$ was immobilized on the surface of polyethylene glycol(M.W. 2000) grafted polyurethane film using diisocyanate in an attemp to develop enzyme immobilized polymeric materials. The surface morphology of the modified polyurethane film was examined by SEM. Effects of pH and temperature on the activity of the immobilized ${\alpha}-amylase$ were investigated. The optimal pH range of the activity was $7.0{\sim}7.5.$ The immobilized ${\alpha}-amylase$ demonstrated high thermal stability and maintained consistent activity during long-term storage.