title: Enzymatic saccharification of Eucalyptus bark using hydrothermal pre-treatment with carbon dioxide.
abstract: In this study, saccharification of the inner bark of Eucalyptus was carried out by enzymatic hydrolysis to produce bioethanol from non-food biomass. To enhance the accessibility of the enzyme to the polysaccharides such as cellulose and holocellulose in the cell wall of the bark, the bark was subjected to hydrothermal pre-treatment with carbon dioxide. This pre-treatment considerably influenced enzymatic hydrolysis. The main component (over 90%) of the generated monosaccharide was glucose, and the yield of glucose on the basis of alpha-cellulose reaches about 80%. This result suggests that the secondary wall, whose main component is cellulose, was effectively hydrolyzed by the enzyme. Microscopic analysis revealed that after pre-treatment, the phloem parenchyma cell had a considerably swollen primary wall and the phloem fibre showed many nano-clefts within its secondary wall. These structural changes appeared to promote enzymatic hydrolysis, because of high accessibility of enzymes to cellulose in the secondary wall.
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusaku, Nagoya 464-8601, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Keiji
authors.initials: K
authors.lastname: Takabe
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Awano
authors.forename: Arata
authors.initials: A
authors.lastname: Yoshinaga
authors.forename: Masashi
authors.initials: M
authors.lastname: Kato
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Furujyo
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fukushima
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002129:Calcium Oxalate / Q000737:chemistry; D002241:Carbohydrates / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry; D004798:Enzymes / Q000737:chemistry; D005052:Eucalyptus / Q000378:metabolism*; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D009005:Monosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D004798:Enzymes; D009005:Monosaccharides; D011134:Polysaccharides; D002245:Carbon Dioxide; D002129:Calcium Oxalate; D002482:Cellulose; D005947:Glucose