Influence of lignin content on enzymatic saccharification of poplar wood chips by different pretreatment methods

Bioconversion of lignocellulose to fermentable sugars is a promising approach to produce potential bio-based energy and chemicals. Pretreatment is the key step to remove or delocalize lignin in lignocellulose, thus improving enzymatic saccharification efficiency. In this study, three kinds of pretreatment methods (ethanol, bisulfite and sulfate) were employed to produce substrates with various lignin contents which were subsequently subjected to biological saccharification processes. Results showed that a lower lignin content led to a higher fermentable sugar yield based on reducing sugar release for all samples. Additionally, the sulfate pretreatment improved the enzymatic saccharification efficiency in a greater extent than the others. Fourier transform infrared (FTIR) spectroscopy confirmed the structure changes during pretreatment.