|
|
|
|
| |
|
|
Cordeiro,Carlos Alberto Martins; Martins,Meire Lelis Leal; Luciano,Angélica Bárbara. |
alpha-amylase (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) production by thermophilic Bacillus sp strain SMIA-2 cultivated in liquid media containing soluble starch reached a maximum at 48h, with levels of 57U/mL. Studies on the a-amylase characterization revealed that the optimum temperature for activity was 70ºC. The enzyme was stable for 2h at 50ºC, while at 60ºC, 70ºC and 90ºC, 4%, 13% and 38% of the original activities were lost, respectively. The optimum pH of the enzyme was 7.5. After incubation of crude enzyme solution for 24h at pH 7.5, a decrease of about 5% of its original activity was observed. The enzyme was strongly inhibited by Co2+, Cu2+ and Ba2+, but less affected by Ca2+, Mg2+, Ni2+, Sr2+ and Mn2+. The enzyme in 1M and 5M NaCl... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alpha-amylase; Thermophilic bacterium; Bacillus sp.. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000100012 |
| |
|
| |
|
|
Bravo Rodríguez,Vicente; Jurado Alameda,Encarnación; Martínez Gallegos,Juan Francisco; Reyes Requena,Antonia; García López,Ana Isabel; Sampaio Cabral,Joaquim Manuel; Fernandes,Pedro; Pina da Fonseca,Luis Joaquim. |
The influence of different commercial surfactants on the enzymatic activity of a commercial alpha-amylase from Bacillus licheniformis (Termamyl 300 L) has been studied. As non-ionic surfactants, alkyl polyglycosides (Glucopon® 215, Glucopon® 600 and Glucopon® 650) were studied, as were fatty alcohol ethoxylates (Findet 1214N/23 and Findet 10/15), and nonyl phenol ethoxylate (Findet 9Q/21.5NF). Also, an anionic surfactant, linear alkyl benzene sulfonate (LAS) was assayed. In general, none of the non-ionic surfactants studied, except Findet 10/15, vary substantially the enzymatic activity. Findet 10/15 has the strongest hydrophobic character and reduces the enzymatic activity more significantly the greater its concentration. Regarding LAS, this surfactant... |
Tipo: Journal article |
Palavras-chave: Alpha-amylase; Alkyl polyglycosides; Enzymatic activity; Fatty alcohol ethoxylates; Linear alkyl benzene sulfonate; Nonyl phenol ethoxylate. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000500012 |
| |
|
|
Huvet, Arnaud; Jeffroy, Fanny; Daniel, Jean-yves; Quere, Claudie; Le Souchu, Pierrick; Van Wormhoudt, A.; Boudry, Pierre; Moal, Jeanne; Samain, Jean-francois. |
In the oyster Crassostrea gigas consumption-related traits, amylase properties and growth were found to be linked through genotypes that differed for polymorphism in the two amylase genes AMYA and AMYB. Modulation of AMYA mRNA level had already been observed in response to food availability, whereas the functional role of AMYB was still unknown. To improve knowledge about the regulation of amylase expression in C. gigas and the respective roles of the two genes, we made an assay of amylase expression at mRNA and enzymatic levels in the digestive gland of oysters that had received dietary supplements of starch. After 18 days, a significant increase of translatable mRNA for AMYB was observed, with a correlated increase in Michaelis-Menten constant Km values... |
Tipo: Text |
Palavras-chave: Alpha-amylase; Crassostrea gigas; Digestive enzyme; Michaelis-Menten constant; Regulation. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19869/17521.pdf |
| |
|
|
Matsushita, Koki; Santiago, Dennis Marvin; Noda, Tatsuya; Tsuboi, Kazumasa; Kawakami, Sakura; Yamauchi, Hiroaki. |
Whole wheat flour (WWF) contains various kinds of functional ingredients, such as dietary fiber, resistant starch, minerals, etc., and bread containing WWF is in great demand in many countries because of its health benefits. Although dough with WWF often results in lower quality bread, previous studies suggested that this could be improved by the addition of suitable enzymes. This study investigated the effects of WWF substitution and enzyme treatments using alpha-amylase (AM) and hemicellulase (HC) on bread making qualities. Results showed that the addition of WWF produced dough with low gas retention of dough (GRD) and specific loaf volume (SLV). However, AM and HC drastically improved both GRD and SLV of WWF-substituted dough and bread by degrading... |
|
Palavras-chave: Whole wheat flour; Bread making quality; Alpha-amylase; Hemicellulase; Enzyme. |
Ano: 2017 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4486 |
| |
|
|
Vieira,Antônio Rodrigues; Vieira,Maria das Graças Guimarães Carvalho; Fraga,Antônio C.; Oliveira,João Almir; Santos,Custódio D. dos. |
To evaluate the effectiveness of gibberellic acid (GA3) in breaking rice seed dormancy and the use of alpha-amylase enzyme activity as an indicator of the dormancy level, seed from the intensively dormant irrigated cultivar Urucuia were used. The seeds were submitted to a pre-drying process in a forced air circulation chamber under 40ºC during 7 days and submersed in 30 mL of GA3 solution under 0, 10, 30 and 60 mg/L H2O concentrations, during 2, 24 and 36 hours. After the treatments, the alpha-amylase activity was determined by using the polyacrilamide electrophoresis and spectrophotometry. At the same time, the germination test was made. The results indicated a gain in germination and in alpha-amylase activity in higher concentrations and soaking time of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rice seeds; Dormancy; Germination; Gibberellic acid (GA3); Alpha-amylase. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222002000200008 |
| |
|
| |
|
|
|