Abstract
Three types of preparations – enzyme immobilized on Eupergit C, cross-linked enzyme crystals (CLECs) and lyophilized enzyme – have been obtained from Trametes pubescens laccase. Their activity in organic solvents has been comparatively evaluated, whereby the CLECs showed a significantly higher activity compared to the immobilized and the lyophilized variant. The soluble, lyophilized laccase and the CLECs were compared for their activity in the oxidation of cellulose in the laccase/TEMPO system. The “double heterogeneous” CLEC system – both the CLECs and the cellulose substrates are solids and only the mediator is homogeneously dissolved – showed similar reactivity to the conventional enzyme system. Laccase CLECs, being a solid, robust and highly active immobilized enzyme form can be conveniently used to modify (protected) low-molecular weight carbohydrates or cellulosics also in (aqueous-)organic media, and they offer many practical advantages: operational stability and ease of recycling coupled with high volumetric productivity.
©2009 by Walter de Gruyter Berlin New York