Ionic liquid-mediated selective extraction of lignin from wood leading to enhanced enzymatic cellulose hydrolysis

Biotechnol Bioeng. 2009 Apr 1;102(5):1368-76. doi: 10.1002/bit.22179.


Lignocellulose represents a key sustainable source of biomass for transformation into biofuels and bio-based products. Unfortunately, lignocellulosic biomass is highly recalcitrant to biotransformation, both microbial and enzymatic, which limits its use and prevents economically viable conversion into value-added products. As a result, effective pretreatment strategies are necessary, which invariably involves high energy processing or results in the degradation of key components of lignocellulose. In this work, the ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][CH3COO]), was used as a pretreatment solvent to extract lignin from wood flour. The cellulose in the pretreated wood flour becomes far less crystalline without undergoing solubilization. When 40% of the lignin was removed, the cellulose crystallinity index dropped below 45, resulting in > 90% of the cellulose in wood flour to be hydrolyzed by Trichoderma viride cellulase. [Emim] [CH3COO] was easily reused, thereby resulting in a highly concentrated solution of chemically unmodified lignin, which may serve as a valuable source of a polyaromatic material as a value-added product.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biotechnology / methods*
  • Cellulose / metabolism*
  • Extraction and Processing Industry / methods*
  • Hydrolysis
  • Imidazoles / chemistry
  • Lignin / isolation & purification*
  • Solvents / chemistry
  • Trichoderma / metabolism*
  • Wood / chemistry*


  • Imidazoles
  • Solvents
  • Cellulose
  • Lignin
  • 1-ethyl-3-methylimidazolium