Air was sparged at 0.5–1 vvm to provide dissolved oxygen concentrations within 20–40% of the saturated level. Samples were withdrawn every 12 h for quantification of FPase, Avicelase, CMCase and -glucosidase activities, as described by Eveleigh et al. (2009), NREL (Adney and Baker, 1996) and Ghose (1987). Total protein content was measured using the Bio-Rad protein assay (Bio-Rad Laboratories), which is based on the Bradford method. BSA was used as standard. All experiments were performed in duplicate and the samples analyses were performed in triplicate.