title: Synergistic effect of delignification and treatment with the ionic liquid 1-ethyl-3-methylimidazolium acetate on enzymatic digestibility of poplar wood.
abstract: This study examined the effects of removing key recalcitrance factors by ionic liquid (IL) treatment on the cellulase digestibility of poplar wood. Ground biomass was subjected to chlorite delignification and IL (1-ethyl-3-methylimidazolium acetate) treatment alone or in combination. The compositional and structural features of differentially treated biomass samples and their hydrolysis performance at various cellulase loadings were investigated. IL treatment caused minor compositional changes but drastically decreased cellulose crystallinity; in particular, when administered after delignification, an X-ray diffractogram similar to that of cellulose II polymorph was observed, suggesting that in the absence of lignin, the cellulose was dissolved in the IL and regenerated in water with a polymorphic transformation. The structural changes induced by the combined delignification-IL treatment facilitated the enzymatic hydrolysis of cellulose; the biomass could be fully degraded within 72 h by 4 FPU of cellulase per gram glucan, with cellobiose degradation being the rate-limiting step.
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, 3-11-32 Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan.
authors.forename: Long
authors.initials: L
authors.lastname: Wu
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, 3-11-32 Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kumagai
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, 3-11-32 Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan; Department of Forest Biomaterials Engineering, College of Forest and Environmental Sciences, Kangwon National University, Chunchen 200-701, Republic of Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, 3-11-32 Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan. Electronic address: t-endo@aist.go.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Endo
mesh_terms: D018533:Biomass; D002475:Cellobiose / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism*; D005936:Glucans / Q000032:analysis; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology*; D008031:Lignin / Q000302:isolation & purification*; D032107:Populus / Q000187:drug effects*; D014934:Wood / Q000187:drug effects*; D014961:X-Ray Diffraction; D014990:Xylans / Q000032:analysis; D014994:Xylose / Q000378:metabolism
chemical_list: D005936:Glucans; D007093:Imidazoles; D014990:Xylans; D002475:Cellobiose; D008031:Lignin; D014994:Xylose; D002480:Cellulase; D005947:Glucose; C518739:1-ethyl-3-methylimidazolium
keywords: Accessibility; Bioenergy; Ethanol; Polymorph; Saccharification