Enzymatic hydrolysis of cellulose materials treated with ionic liquid [BMIM] Cl

Abstract

A new cellulose solvent ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was used to treat wheat straw and steam-exploded wheat straw (SEWS) in order to improve the enzymatic hydrolysis rates, while the water was used as the control. The enzymatic hydrolysis results showed that the hydrolysis rates of materials treated with [BMIM]Cl were improved. The hydrolysis rate of treated wheat straw could reach 70.37% and the SEWS could be completely hydrolyzed, while hydrolysis rates of the wheat straw and SEWS treated with water were 42.78% and 68.78% under the same conditions, respectively. The FTIR analysis and polymerization degree measurement indicated that the hydrolysis rates improvement was attributed to the decrease of the polymerization degrees of cellulose and hemicellulose, the absolute crystallinity degree of cellulose and the increase of its reaction accessibility.

Evaluation of the biocompatibile ionic liquid 1-methyl-3-methylimidazolium dimethylphosphite pretreatment of corn cob for improved saccharification

“…3b). Based on the FTIR data, the decreases of LOI and TCI indexes had been similarly reported for wheat straw regenerated from IL [Bmim]Cl dissolution (Liu and Chen 2006). According to the SEM data, it is evident that the fibers were partially disrupted, instead of clearly isolated, individual fibers, which are characteristic for untreated corn cob.…”

“…Very recently, ILs showed promise as efficient novel solvents for pretreatment of cellulosic materials Liu and Chen 2006). In addition, residue of ionic liquid from the pretreatment may follow the cellulose fibers to the enzymatic hydrolysis and fermentation process.…”

“…Until recently, ionic liquids (ILs), so-called green solvents, have been confirmed to be efficient for lignocellulosic materials, such as cellulose, wood, or wheat straw (Dadi et al 2006;Liu and Chen 2006;Diego et al 2007). The cellulosic materials regenerated from ILs were found essentially amorphous and porous and were much more prone to degradation by cellulases Dadi et al 2006).…”

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

“…For example, cellulose reconstituted after being dissolved in [Amim][Cl] and [Bmim][Cl] had lower degrees of crystallinity than native cellulose, which resulted in greater accessibility of the polysaccharide chains to cellulases, and thus more facile hydrolysis than was achieved without initial dissolution in and reconstitution from an IL (Dadi et al, 2006(Dadi et al, , 2007Liu and Chen, 2006). More recently, several groups have reported the dissolution of full lignocellulosic materials such as corn stalks, rice straw, bagasse, pine wood, and spruce wood in ILs followed by cellulose hydrolysis with acid or enzymes (Fort et al, 2007;Kilpeläinen et al, 2007;Li et al, 2008).…”

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

“…ILs are efficient for biomass dissolution, which is typically reported as a change in crystallinity index (CrI) (Kumar et al 2009;Segal et al 1959;Thygesen et al 2005). For example, the degrees of crystallinity in cellulose reconstituted after being dissolved in 1-allyl-3-methylimidazolium chloride ([C 3 C 1 Im]Cl) and 1-butyl-3-methylimidazolium chloride ([C 4 C 1 Im]Cl) were lower than untreated cellulose, resulting in an increased accessibility of the polysaccharide chains to cellulases (Dadi et al 2007;Dadi et al 2006;Liu and Chen 2006). A reduction in crystallinity was observed after IL pretreatment of switchgrass, maple wood, yellow pine, and hardwood red oak (Lee et al 2009;Li et al 2010;Sun et al 2009).…”