Publications by authors named "Natalia G Graebin"

β-Glucosidases from two different commercial preparations, Pectinex Ultra SP-L and Celluclast® 1.5L, were immobilized on divinylsulfone (DVS) supports at pH 5.0, 7.

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Three β-glucosidases (Pectinex Ultra SP-L, Pectinex Ultra Clear and homemade preparation from Aspergillus niger) were immobilized using different strategies: ionic adsorption on aminated (MANAE)-agarose beads at pH 5, 7, and 9, followed by biocatalysts modification with glutaraldehyde, or on glutaraldehyde pre-activated supports. The pH of the immobilization was altered to allow different enzyme molecule orientations on the support surface. The biocatalysts from Pectinex Ultra SP-L showed the highest thermal and operational stabilities when immobilized on MANAE-agarose-glutaraldehyde at pH 7.

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Glycoside hydrolases (GH) are enzymes capable to hydrolyze the glycosidic bond between two carbohydrates or even between a carbohydrate and a non-carbohydrate moiety. Because of the increasing interest for industrial applications of these enzymes, the immobilization of GH has become an important development in order to improve its activity, stability, as well as the possibility of its reuse in batch reactions and in continuous processes. In this review, we focus on the broad aspects of immobilization of enzymes from the specific GH families.

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A new biocatalyst of lipase B from Candida antarctica (MCI-CALB) immobilized on styrene-divinylbenzene beads (MCI GEL CHP20P) was compared with the commercial Novozym 435 (immobilized lipase) in terms of their performances as biocatalysts for the esterification of acetic acid and n-butanol. The effects of experimental conditions on reaction rates differed for each biocatalyst, showing different optimal values for water content, temperature, and substrate molar ratio. MCI-CALB could be used at higher acid concentrations, up to 0.

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