Journal of Microbiology

Research Support, Non-U.S. Gov't

Purification and Characterization of the α-Glucosidase Produced by Thermophilic Fungus Thermoascus aurantiacus CBMAI 756: Ana Flávia Azevedo Carvalho , Maurício Boscolo , Roberto da Silva , Henrique Ferreira , Eleni Gomes; J. Microbiol. 2010;48(4):452-459. Published online August 20, 2010; DOI: https://doi.org/10.1007/s12275-010-9319-2

Abstract: Αn α-glucosidase enzyme produced by the fungus Thermoascus aurantiacus CBMAI 756 was purified by ultra filtration, ammonium sulphate precipitation, and chromatography using Q Sepharose, Sephacryl S-200, and Superose 12 columns. The apparent molecular mass of the enzyme was 83 kDa as determined in gel electrophoresis. Maximum activity was observed at pH 4.5 at 70°C. Enzyme showed stability stable in the pH range of 3.0-9.0 and lost 40% of its initial activity at the temperatures of 40, 50, and 60°C. In the presence of ions Na+, Ba2+, Co2+, Ni2+, Mg2+, Mn2+, Al3+, Zn2+, Ca2+ this enzyme maintained 90-105% of its maximum activity and was inhibited by Cr3+, Ag+, and Hg2+. The enzyme showed a transglycosylation property, by the release of oligosaccharides after 3 h of incubation with maltose, and specificity for short maltooligosaccharides and α-PNPG. The Km measured for the α-glucosidase was 0.07 μM, with a Vmax of 318.0 μmol/min/mg.

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