The ball-milling (BM)-treated sample (1%) was hydrolyzed with an enzyme cocktail (40 FPU/g substrate) for 72 hours as described in materials and methods. BM treatment was performed using pulverisette 7. The hydrolysis yields of glucose and xylose are calculated based on the glucan and xylan contents, respectively, in the dry weight of untreated biomass. Total yield of hydrolyzed sugars is calculated from the combined contents of glucan and xylan in the dry weight of untreated biomass. aCrystallinity index of the BM-treated sample.