Conversion during hydrolysis of pretreated spruce for different impeller speeds. (A, B) Conversion during hydrolysis of pretreated spruce (10% water-insoluble solids; WIS) for different impeller speeds (squares = 500 rpm; stars = 300 rpm; circles = 150 rpm; crosses = 75 rpm, diamonds = 25 rpm). (C, D) Conversion at different impeller speeds for three selected times (Circles = 96 hours, diamonds = 48 hours, squares = 24 hours). (A, C) Solid lines = enzyme load of 20 FPU/g glucan; (B, D) dashed lines = 10 FPU/g glucan. The SD in the measured concentrations was < 4.2% for the duplicates.