A specific short dextrin-hydrolyzing extracellular glucosidase from the thermophilic fungus Thermoascus aurantiacus 179-5.
J Microbiol
; 44(3): 276-83, 2006 Jun.
Article
in En
| MEDLINE
| ID: mdl-16820757
ABSTRACT
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 (alpha-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II alpha-glucosidase. The optimum temperature of the enzyme was 70 degrees . In addition, the enzyme was highly thermostable (100% stability for 10 h at 60 degrees and a half-life of 15 min at 80 degrees), and stable within a wide pH range.
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Database:
MEDLINE
Main subject:
Eurotiales
/
Dextrins
/
Glucosidases
/
Hot Temperature
Language:
En
Year:
2006
Type:
Article