The sugar yield obtained at different conditions was incorporated into the Eq. (10) as described in Supplementary Materials to calculate the stover sugar hydrolysate production costs. The conditions which could obtain a relative lower sugar production cost was chosen for the following experiments. The pretreated corn stover was used directly for enzymatic hydrolysis without any other detoxification process. All the enzymatic hydrolysis trials were performed in duplicates and the average data were reported.