Pretreatment of Bamboo by Ammonium Sulfite for Efficient Enzymatic Hydrolysis

Abstract

In order to find out the potential effect of ammonium sulfite pretreatment on bamboo for efficient enzymatic saccharification, various ammonium sulfite loadings were conducted to pretreat bamboo at 180 °C for 1–8 h with the solid–liquid ratio of 1:6, respectively. The results verified that ammonium sulfite pretreatment could effectively disrupt the recalcitrance of bamboo and create highly enzymatic hydrolysis sugar yield for further utilization. The contents of lignin in the substrates decreased significantly (from 22.94% to 1.21%) after pretreated and the higher lignin removal with higher chemical loading and longer reaction time during pretreatment. The cellulose-to-glucose conversion yield of pretreated bamboo substrates could achieve almost 100% within 48 h by enzymes loading of 15 FPU of cellulase and 30 IU of β-glucosidase per gram glucan. Therefore, ammonium sulfite pretreatment is argued to be a potential alternative technology for pretreatment of bamboo.