A Comparison of Low Temperature Alkali and High Temperature Acid Pretreatments for Improving Saccharification of Spent Mushroom Substrate

Low temperature alkali (LTA) pretreatment and high temperature acid (HTA) pretreatment methods were applied to spent mushroom substrate (SMS) for providing comparative performance data on the enhancement of enzymatic saccharification and the change of composition and structure. LTA pretreatment contributed to higher lignin removal (67.6%) and enzymatic digestibility (85.6%) during enzymatic hydrolysis, while HTA pretreatment resulted in higher hemicellulose reduction (85.3%) but lower enzymatic digestibility (43.5%). The physical structure was destroyed at certain degree and changes in cellulose crystallinity occurred after both LTA and HTA pretreatments. Besides, the effect of lignin reduction in alkali pretreatment on glucose yield was studied. These results indicated that LTA pretreatment had the potential to be developed into a cost effective process for producing bioproducts from lignocellulosic materials.