title: Mechanical milling and membrane separation for increased ethanol production during simultaneous saccharification and co-fermentation of rice straw by xylose-fermenting Saccharomyces cerevisiae.
abstract: Mechanical milling and membrane separation were applied to simultaneous saccharification and co-fermentation from hydrothermally pretreated rice straw. Mechanical milling with minimized 4 cycles enabled 37.5±3.4gL(-1) and 45.3±4.4gL(-1) of ethanol production after 48h by xylose-fermenting Saccharomyces cerevisiae from solid fractions (200 and 250gL(-1)) of pretreated rice straw with 5 filter paper unitg-biomass(-1) cellulase (respectively, 77.3±7.1% and 74.7±7.3% of theoretical ethanol yield). Use of a membrane-based process including nanofiltration and ultrafiltration increased the sugar concentrations in the liquid fraction of pretreated rice straw and addition of this liquid fraction to 250gL(-1) solid fraction increased ethanol production to 52.0±0.4gL(-1) (73.8±0.6% of theoretical ethanol yield). Mechanical milling was effective in increasing enzymatic hydrolysis of the solid fraction and membrane separation steps increased the ethanol titer during co-fermentation, leading to a proposal for combining these processes for ethanol production from whole rice straw.
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 675-8501, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 675-8501, Japan.
authors.forename: Yota
authors.initials: Y
authors.lastname: Tsuge
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 675-8501, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sasaki
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Teramura
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 675-8501, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Inokuma
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 675-8501, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hasunuma
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan; Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. Electronic address: akondo@kobe-u.ac.jp.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D056804:Biofuels; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry*; D005285:Fermentation; D006868:Hydrolysis; D008567:Membranes, Artificial; D012275:Oryza; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D014994:Xylose / Q000737:chemistry*
chemical_list: D056804:Biofuels; D002241:Carbohydrates; D008567:Membranes, Artificial; D000431:Ethanol; D014994:Xylose
keywords: Ethanol; Mechanical milling; Nanofiltration; Rice straw; Ultrafiltration