Fig. 1

Cellulose conversion yields of pretreated spruce (PS -triangles) and pretreated wheat straw (PWS—circles) materials after enzymatic hydrolysis for 72 h with either 15 mg EP/g cellulose Ctec2 enzyme preparation (filled shapes) or 45 mg EP/g cellulose Celluclast/Novozym188 (C/N 5:1) enzyme mix (hollow shapes), from low to high  % DM. For Ctec2-treated samples, cellulose conversion yields remain stable with DM until 15–18% DM, where they begin to decrease, but at different rates for the two materials. For the C/N-treated samples, reductions in cellulose conversion yields begin even at low DM concentrations. This suggests that high-solids effect is influenced by both the enzyme preparation, and the substrate type. Error bars represent ± 1 standard deviation of triplicate experiments