title: Addition of alkali to the hydrothermal-mechanochemical treatment of Eucalyptus enhances its enzymatic saccharification.
abstract: The effects of alkali on hydrothermal-mechanochemical treatment (hydrothermal treatment combined with wet-milling) were examined with the aim of improving pretreatment of lignocellulosic biomass before enzymatic saccharification. After enzymatic saccharification, the highest glucose yield was obtained by autoclaving at 170°C in the presence of 20% NaOH per substrate weight. The wood fiber was unraveled into finer nanofibers by hydrothermal-mechanochemical treatment, thus increasing the specific surface area of the substrate from 11 to 132m(2)/g. Adding 20% NaOH to the treatment further increased the specific surface area of the already fibrillated substrate by 76% (232m(2)/g) due to lignin removal and ester bond cleavage between lignin and hemicellulose. This increase in specific surface area was closely related to the increase in enzymatic digestibility; therefore, NaOH addition may have enhanced the effect of hydrothermal-mechanochemical treatment.
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Ishiguro
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan. Electronic address: t-endo@aist.go.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Endo
mesh_terms: D050260:Carbohydrate Metabolism / Q000187:drug effects*; D002480:Cellulase / Q000378:metabolism*; D005052:Eucalyptus / Q000187:drug effects* / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D012972:Sodium Hydroxide / Q000494:pharmacology*; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature; D014867:Water / Q000494:pharmacology*
chemical_list: D014867:Water; C036909:lignocellulose; D012972:Sodium Hydroxide; D008031:Lignin; D002480:Cellulase; D005947:Glucose
keywords: Fibrillation; Hydrothermal–mechanochemical treatment; Lignocellulosic biomass; Sodium hydroxide