title: Thermal inactivation and reactivity of beta-glucosidase immobilized on chitosan-clay composite.
abstract: The dried and wet chitosan-clay composite beads were prepared by mixing equal weights of cuttlebone chitosan and activated clay and then spraying drop-wise through a syringe, with and without freeze-drying, respectively. These beads were then immersed in 5 g/L of glutaraldehyde solution at a dosage of 0.5 g/L and were cross-linked, which were finally used as supports for beta-glucosidase immobilization. The properties of the enzyme immobilized on wet- and dried-composite beads were compared. Kinetic modeling of thermal inactivation of free and immobilized enzymes was also investigated. For a given enzymatic reaction, the rate constant related to the decomposition of the enzyme-substrate complex to final product and the uncomplexed enzyme using dried-composite immobilized enzyme was larger than those using both free and wet-composite immobilized enzymes.
authors.affiliation: Department of Chemical Engineering, National United University, Miao-Li 36003, Taiwan.
authors.forename: Min-Yun
authors.initials: MY
authors.lastname: Chang
authors.forename: Hsiang-Chien
authors.initials: HC
authors.lastname: Kao
authors.forename: Ruey-Shin
authors.initials: RS
authors.lastname: Juang
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002384:Catalysis; D048271:Chitosan / Q000737:chemistry*; D000077215:Clay; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D027861:Prunus / Q000201:enzymology; D001617:beta-Glucosidase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000538:Aluminum Silicates; D004800:Enzymes, Immobilized; D048271:Chitosan; D001617:beta-Glucosidase; D000077215:Clay