title: Immobilization of dextranase from Chaetomium erraticum.
abstract: In order to facilitate the Co-Immobilization of dextransucrase and dextranase, various techniques for the immobilization of industrial endo-dextranase from Chaetomium erraticum (Novozymes A/S) were researched. Adsorption isotherms at various pH-values have been determined for bentonite (Montmorillonite), hydroxyapatite and Streamline DEAE. Using bentonite and hydroxyapatite, highest activity loads (12,000 Ug(-1); 2900 Ug(-1), respectively) can be achieved without a significant change of the apparent Michaelis-Menten constant K(M). For successful adsorption, enzyme to bentonite ratios greater than 0.4 (w/w) have to be used as lower ratios lead to 90% enzyme inactivation due to bentonite contact. In addition, covalent linkage using the activated oxiran carriers Eupergit C and Eupergit C250L as well as linkage with aminopropyl silica via metaperiodate activation of glycosyl moiety of dextranase are discussed. This is also the first report probing the structure of a matrix containing dextranase by use of substrate species with different molecular weights. From this we can observe a relationship between the porosity of Eupergit and dextran dependent activity. For the reactor concept using Co-Immobilisates, hydroxyapatite will be preferred to Eupergit because of its higher specific activity and dispersity.
authors: Institute for Technical Chemistry, Department for Carbohydrate Technology, Technical University Braunschweig, Hans-Sommer-Strasse 10, D-38106, Braunschweig, Germany.
authors: Frank Alwin
authors: FA
authors: Erhardt
authors: Hans-Joachim
authors: HJ
authors: Jördening
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000378:metabolism; D001546:Bentonite / Q000378:metabolism; D002597:Chaetomium / Q000201:enzymology*; D003910:Dextranase / Q000378:metabolism*; D017886:Durapatite / Q000378:metabolism; D004789:Enzyme Activation; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004983:Ethanolamines / Q000378:metabolism; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012822:Silicon Dioxide / Q000378:metabolism
chemical_list: D000464:Alginates; D004800:Enzymes, Immobilized; D004983:Ethanolamines; D006603:Hexuronic Acids; C021611:aminopropyl silica gel; D001546:Bentonite; D012822:Silicon Dioxide; D020723:Glucuronic Acid; D017886:Durapatite; D003910:Dextranase; C007369:2-diethylaminoethanol