• Proceedings of the KTCVS Conference
• /
• 1998.10a
• /
• pp.13-13
• /
• 1998

• Journal of Life Science
• /
• v.22 no.4
• /
• pp.472-477
• /
• 2012

A thermophilic $Alicyclobacillus$ $acidocaldarius$, which produces thermostable ${\alpha}$-amylase, was isolated from the hot water effluent of a boiled rice mill near Tirupati, Andhra Pradesh, India. The effect of different culture conditions on the growth and production of extracellular ${\alpha}$-amylase by thermophilic $A.$ $acidocaldarius$ was investigated in laboratory scale. The results showed that the optimum conditions for the production of ${\alpha}$-amylase are a temperature of $60^{\circ}C$, pH of 6.0, and medium starch concentration of 1.0%, and yeast extract and tryptone of 0.2%. Surfactants, like Tween-20 and SDS, up to 0.02%, were found to increase the bacterial growth and enzymes. Further increase in their concentration resulted in significantly decreased enzyme production.

• Korean Journal of Food Science and Technology
• /
• v.47 no.6
• /
• pp.797-800
• /
• 2015

The effect of raw wheat flour on starch retrogradation retardation was investigated in a rice starch paste model. Specifically, in terms of amylase activity present in the wheat flour, the retardation effect was investigated depending on reaction temperature (40, 60, and $80^{\circ}C$), incubation time (0, 20, 40, and 60 min), and wheat flour addition levels (0-10%). An increase in wheat flour concentration resulted in a rapid decrease in the elastic modulus (G') as the incubation time increased. The G' changes of the rice starch pastes were furthermore fitted by the first order reaction for the reaction rate estimation on the temperature basis. The experimental reaction rate of the paste sample incubated with 10% wheat flour at $40^{\circ}C$ exhibited good agreement with the predicted value. This result implied that the first order reaction kinetics could be suitable to predict the changes in the G' as a function of incubation temperature and wheat flour concentration.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.05a
• /
• pp.128-129
• /
• 1999

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2001.05a
• /
• pp.120-121
• /
• 2001

• Korean Journal of Microbiology
• /
• v.46 no.1
• /
• pp.80-85
• /
• 2010

Two different ${\alpha}$-amylase isozymes (AMY1 and AMY2) found in barley malt share up to 80% of amino acid sequence identity with each other, but their enzymatic properties differ remarkably. AMY1 shows the highest activity at low concentration of calcium ion, while AMY2 is highly active at high calcium concentration. Meanwhile, BASI (Barley ${\alpha}$-Amylase/Subtilisin Inhibitor) protein specifically inhibits only AMY2. In the present study, three separate regions in AMY genes (I, II, and III) were assigned on the basis of restriction enzyme sites and four kinds of chimeric amylases have been obtained by swapping a part of regions with each other. Each chimera gene was successfully over-expressed in Pichia pastoris. From the results of enzymatic characterization, both AMY211 and AMY122 showed the mixed or intermediate type of calcium-dependent activity between AMY1 and 2. Meanwhile, only AMY221 chimera could be significantly inhibited by BASI protein. As a result, it can be proposed that some amino acid residues in the region I and II, except region III, of barley ${\alpha}$-amylases play very important roles in calcium-dependency and interaction with BASI.

• Journal of Life Science
• /
• v.19 no.10
• /
• pp.1374-1381
• /
• 2009

This study was designed to investigate the differences of physiological variables by age group in alcohol-consuming men. The thirty year old-age group had the lowest waist-hip ratio (WHR), right and left cardio-ankle vascular index (R-CAVI and L-CAVI), right and left ankle-brachial index (R-ABI and L-ABI), amylase, high sensitivity C-reactive protein (hs-CRP), and creatine phosphokinase (CPK) levels, and the highest body weight (BW), interleukin-6 (IL-6), right and left intraocular pressure (R-IP and L-IP), hematocrit (Hct), hemoglobin (Hb), erythrocyte, red blood cells distribution width (RDW), alanine aminotransferase (ALT), total cholesterol (TCH), triglyceride (TG), and ferritin levels. The forty year old-age group was the highest in hs CRp and CPK levels, but the lowest in ferritin level. The fifty year old-age group possessed the highest WHR, diastolic blood pressure (DBP), R- and L-ABI, eosinophil, and amylase levels. The sixty year old-age group had the highest R- and L-CAVI, mean corpuscular volume (MCV), ALP, $\gamma$-glutamyltranspeptidase ($\gamma$-GTP), rheumatoid factor (RF), $\alpha$-fetoprotein (AFP) and prostate specific antigen (PSA) levels and the lowest BW, DBP, R-IP, L-IP, Hct, Hb, leukocyte, platelet, RDW, eosinophil, monocyte, ALT, amylase, TG, and CPK levels. These findings indicate that there may be differences of physiological variables depending on age group in alcohol-consuming men. Further studies should be focused on the physiological differences between alcohol-consuming men and women.

• Microbiology and Biotechnology Letters
• /
• v.38 no.2
• /
• pp.151-157
• /
• 2010

Barley malt produces two different $\alpha$-amylase isozymes (AMY1 and AMY2), which share up to 80% of amino acid sequence identity with each other. However, their enzymatic properties differ remarkably. In this study, five chimeric enzymes between AMY1 and 2 were constructed by staggered extension process (StEP) technique, and their enzymatic properties were characterized. According to the results, chimeric AMY-D2, D8, and E12 showed the mixed or intermediate types of calcium-dependent activity between AMY1 and 2. Meanwhile, only AMY-E10 chimera could be significantly inhibited by barley $\alpha$-amylase/subtilisin inhibitor (BASI) protein. Chimera AMY-C6 showed the same calcium-dependency as AMY1, while AMY-E10 was closely similar to AMY2. As a result, it can be proposed that some amino acid residues in the region II, III, and IV of barley $\alpha$-amylases can play very important roles in the interaction with BASI, and those in III, V, VI, and VII may partly affect on the calcium-dependent activity.

• Microbiology and Biotechnology Letters
• /
• v.42 no.2
• /
• pp.139-144
• /
• 2014

This study examined the efficacies of Cynanchum wilfordii and Phlomis umbrosa extracts on serum insulin like growth factor-I (IGF-I) and bone growth by raising rats in vivo. C. wilfordii and P. umbrosa extracts significantly increased serum IGF-I by 42% and 22% than the control, respectively. Treatment with ${\alpha}$-amylase when manufacturing these extracts remarkably increased the concentration of IGF-I by 63% and 36% above the control, respectively. This meant that these extracts, especially ${\alpha}$-amylase treated extracts, maintained a higher level of IGF-I secretion in the treated groups. In addition, increases of 6% in femur length were found after 8 weeks of oral administration with these extracts. These results indicate that C. wilfordii and P. umbrosa extracts have beneficial effects on bone growth via IGF-I.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2000.04a
• /
• pp.296-297
• /
• 2000