title: Steam explosion treatment for ethanol production from branches pruned from pear trees by simultaneous saccharification and fermentation.
abstract: This study investigated the production of ethanol from unutilized branches pruned from pear trees by steam explosion pretreatment. Steam pressures of 25, 35, and 45 atm were applied for 5 min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after steam explosion at 25, 35, and 45 tm, respectively. These values corresponded to 34.9, 34.3, and 27.1 g of glucose per 100 g of dry steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100 g/L of water- and methanol-washed residues from 35 atm-exploded pear branches was used as substrate.
authors.affiliation: a Department of Life System , Institute of Technology and Science, The University of Tokushima , Tokushima , Japan.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Sasaki
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Okumura
authors.forename: Chikako
authors.initials: C
authors.lastname: Asada
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D056804:Biofuels / Q000382:microbiology; D050260:Carbohydrate Metabolism; D002480:Cellulase / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D007716:Kluyveromyces / Q000378:metabolism; D031989:Pyrus / Q000737:chemistry*; D013227:Steam; D014197:Trees / Q000737:chemistry*
chemical_list: D056804:Biofuels; D013227:Steam; D000431:Ethanol; D002480:Cellulase
keywords: enzymatic saccharification; ethanol production; pruned pear branches; steam explosion