Purification and properties of beta-glucosidase from Aspergillus terreus

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6125112

Workman, W E; Day, D F

A beta-glucosidase (EC 3.2.1.21) from the fungus Aspergillus terreus was purified to homogeneity as indicated by disc acrylamide gel electrophoresis. Optimal activity was observed at pH 4.8 and 50 degrees C. The beta-glucosidase had Km values of 0.78 and 0.40 mM for p-nitrophenyl-beta-D-glucopyranoside and cellobiose, respectively. Glucose was a competitive inhibitor, with a Ki of 3.5 mM when p-nitrophenyl-beta-D-glucopyranoside was used as the substrate. The specific activity of the enzyme was found to be 210 IU and 215 U per mg of protein on p-nitrophenyl-beta-D- glucopyranoside and cellobiose substrates, respectively. Cations, proteases, and enzyme inhibitors had little or no effect on the enzyme activity. The beta-glucosidase was found to be a glycoprotein containing 65% carbohydrate by weight. It had a Stokes radius of 5.9 nm and an approximate molecular weight of 275,000. The affinity and specific activity that the isolated beta-glucosidase exhibited for cellobiose compared favorably with the values obtained for beta-glucosidases from other organisms being studied for use in industrial cellulose saccharification. (Refs. 34).

• Research Organization: Dept of Microbiology and Audubon Sugar Inst, Louisiana State Univ, Baton Rouge, LA 70803
• OSTI ID: 6125112
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 44:6; ISSN AEMID
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ASPERGILLUS
CARBOHYDRATES
CELLOBIOSE
DISACCHARIDES
ELECTROPHORESIS
ENZYMES
FUNGI
GLUCOSE
GLUCOSIDASE
GLYCOSYL HYDROLASES
HEXOSES
HYDROLASES
MONOSACCHARIDES
O-GLYCOSYL HYDROLASES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
PROTEINS
PURIFICATION
SACCHARIDES
SUBSTRATES