Fig. 5

Effects of cell feeding on SSCF performance. Feeding cells improved the overall performance of fed-batch SSCF process (filled triangles) compared to loading all cells initially at 0 h (open triangles), in 15 % (w/w) final accumulated WIS addition (a), 22 % (w/w) final WIS with unoptimized addition of solids and insufficient mixing after 24 h (b), and 22 % (w/w) final WIS with optimized addition of solids and efficient mixing (c). At high accumulated WIS concentration, stress induced by inhibitors and ethanol is more severe than at low WIS contents. Consequently, the benefit of feeding cells instead of adding them all initially was clearer. The arrows indicate addition of yeast cells in the experiments represented with filled triangles. The error bars indicate standard deviation of duplicate experiments