Total glucose yields, as fraction of theoretical maximum glucose produced, for 4 rounds of hydrolysis for the response surface experiment on PCS substrate. 72 hr reaction time between recycles, initial 15% TS loading, and 51.4 mg EP/g cellulose initial enzyme loading. Reaction conditions varied by the fraction of insoluble solids recycled (%), and the amount of makeup enzyme product added per gram cellulose added with each recycle (mg EP/g). Values are averages of duplicate experiments. Error bars are ± one standard deviation of 6 center point experiments. The red bar represents the glucose yield at 72 hours with no recycle and 51.4 mg EP/g cellulose. Roman letters a-d indicate significantly different values by ANOVA (95% confidence intervals, pooled standard deviation 1.722 (N=22)).