| Autor: |
Silva TM; Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Monte Alegre, 14.040-901, Ribeirão Preto, SP, Brazil., Damásio AR, Maller A, Michelin M, Squina FM, Jorge JA, Polizeli Mde L |
| Jazyk: |
angličtina |
| Zdroj: |
Folia microbiologica [Folia Microbiol (Praha)] 2013 Nov; Vol. 58 (6), pp. 495-502. Date of Electronic Publication: 2013 Mar 06. |
| DOI: |
10.1007/s12223-013-0230-1 |
| Abstrakt: |
An extracellular amylase secreted by Aspergillus niveus was purified using DEAE fractogel ion exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5 % polyacrylamide gel electrophoresis (PAGE) and 10 % sodium dodecyl sulfate (SDS-PAGE). The enzyme exhibited 4.5 % carbohydrate content, 6.6 isoelectric point, and 60 and 52 kDa molar mass estimated by SDS-PAGE and Bio-Sil-Sec-400 gel filtration column, respectively. The amylase efficiently hydrolyzed glycogen, amylose, and amylopectin. The end-products formed after 24 h of starch hydrolysis, analyzed by thin layer chromatography, were maltose, maltotriose, maltotetraose, and maltopentaose, which classified the studied amylase as an α-amylase. Thermal stability of the α-amylase was improved by covalent immobilization on glyoxyl agarose (half-life of 169 min, at 70 °C). On the other hand, the free α-amylase showed a half-life of 20 min at the same temperature. The optima of pH and temperature were 6.0 and 65 °C for both free and immobilized forms. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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