All samples were autoclaved at 121 °C, 15 lb/in2 for 15
min. In the case of two steps pretreatments, the biomass
was firstly pretreated with 2% w/v NaOH in 250 mL
duran bottle, autoclaved at 121 °C, 15 lb/in2 for 15 min.
After cooled down, they were washed with water and
filtered through muslin cloth. The solid residues were
further pretreated with 2% w/v H2SO4 in 250 mL duran
bottle, autoclaved at the same condition. Finally, the
pretreated solid residues of all experiments were then
washed with water, adjusted to pH 5.0 and used as
substrate for enzymatic saccharification.