Cellobiose and salicin were continuously hydrolysed in a packed bed reactor containing Trichoderma sp. E-58, encapsulated in calcium alginate beads. Continuous β-glucosidase activities were measured using inlet substrate concentrations of 10 mM and 35 mM for cellobiose and salicin respectively. Maximal activities achieved using the described immobilization procedure were between 70 and 90 μmoles substrate reacted per minute per liter of bead volume. Immobilized mycelial-associated β-glucosidase activity was shown to have a half-life of greater than 1000 hours when operating continuously at 50°C.