2021 Annual Meeting

(519g) Lignin-Based Deep Eutectic Solvent Pretreatment of Transgenic Sweet Sorghum Bagasse to Achieve a Sustainable Biorefinery Process

Authors

Yang Tian, Lawrence Berkeley National Laboratory
Linjing Jia, SUNY College of Environmental Science and Forestry
Aymerick Eudes, Joint BioEnergy Institute, Lawrence Berkeley National Laboratory
Kwang Ho Kim, University of British Columbia
Yunqiao Pu, Oak Ridge National Laboratory
Gyu Leem, State University of New York College of Environmental Science and Forestry
Deepak Kumar, SUNY College of Environmental Science and Forestry
Arthur Ragauskas, University of Tennessee
Chang Geun Yoo, State University of New York College of Environmen
Conversion efficiency is one of technical and economic obstacles in lignocellulosic biomass utilization. In this study, a closed-loop process with lignin-derived deep eutectic solvent (DES) pretreatment and genetically modified p­-Hydroxybenzoic acid (PB)-rich sweet sorghum bagasse was investigated. DES synthesized with choline chloride (ChCl) and PB has shown high pretreatment efficiency. Results show that ChCl-PB DES effectively fractionated both wild-type and transgenic sweet sorghum bagasse at mild temperatures. The cellulase accessibility was significantly improved after the pretreatment. Formation of aqueous DES with a small quantity of water enhanced its pretreatment performance further. Recovered lignin was characterized with two-dimensional heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR), 31P NMR, and gel permeation chromatography (GPC) to understand the interaction between DES and biomass. The pretreatment preserved about half of the amount of β-O-4 linkage with relatively uniform sizes and low molecular weight. No condensed lignin unit was observed. This study indicates that the integration of lignin-based DES with genetic engineering is a promising strategy to develop a sustainable biorefinery process.