Fig. 3

Fitting and validation of enzymatic hydrolysis model. a and b Concentrations of residual WIS (a) and of glucose (b) after fitting the hydrolysis model to batch experiments at 10 % (w/w) WIS using enzyme dosages of 5 (blue), 10 (red) and 15 (green) FPU (g WIS)−1. c–e Validation of the model was carried out by simulating the time course of glucose (squares and dotted lines) and xylose (stars and dashed lines) concentrations in a separate set of experiments using 15 % WIS and 10 FPU (g WIS)−1 in batch mode (c), fed-batch with all enzymes added initially (d) and fed-batch with enzymes added proportionally to substrate (e). Simulations are illustrated in lines and experiments in symbols. The coefficients of regression (R 2) are listed in each sub figure