A specific short dextrin-hydrolyzing extracellular glucosidase from the thermophilic fungus Thermoascus aurantiacus 179-5
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Data
2006-12-13
Autores
Azevedo Carvalho, Ana Flávia [UNESP]
Zorzetto Gonçalves, Aline [UNESP]
Da Silva, Roberto [UNESP]
Gomes, Eleni [UNESP]
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Resumo
The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (α-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II α-glucosidase. The optimum temperature of the enzyme was 70°C. In addition, the enzyme was highly thermostable (100% stability for 10 h at 60°C and a half-life of 15 min at 80°C), and stable within a wide pH range. Copyright © 2006, The Microbiological Society of Korea.
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Palavras-chave
Glucosidase, Solid-state fermentation, Submerged fermentation, Thermoascus, Thermophilic, Thermostable, Fungi, Manihot esculenta, Thermoascus aurantiacus, Triticum aestivum, dextrin, glucosidase, culture medium, enzyme specificity, enzyme stability, enzymology, Eurotiales, fermentation, growth, development and aging, heat, hydrolysis, metabolism, pH, Culture Media, Dextrins, Enzyme Stability, Fermentation, Glucosidases, Heat, Hydrogen-Ion Concentration, Hydrolysis, Substrate Specificity
Como citar
Journal of Microbiology, v. 44, n. 3, p. 276-283, 2006.