title: Simultaneous saccharification and fermentation of steam exploded duckweed: Improvement of the ethanol yield by increasing yeast titre.
abstract: This study investigated the conversion of Lemna minor biomass to bioethanol. The biomass was pre-treated by steam explosion (SE, 210°C, 10 min) and then subjected to simultaneous saccharification and fermentation (SSF) using Cellic® CTec 2 (20 U or 0.87 FPU g(-1) substrate) cellulase plus β-glucosidase (2 U g(-1) substrate) and a yeast inoculum of 10% (v/v or 8.0×10(7) cells mL(-1)). At a substrate concentration of 1% (w/v) an ethanol yield of 80% (w/w, theoretical) was achieved. However at a substrate concentration of 20% (w/v), the ethanol yield was lowered to 18.8% (w/w, theoretical). Yields were considerably improved by increasing the yeast titre in the inoculum or preconditioning the yeast on steam exploded liquor. These approaches enhanced the ethanol yield up to 70% (w/w, theoretical) at a substrate concentration of 20% (w/v) by metabolising fermentation inhibitors.
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
authors.forename: X
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
authors.forename: G K
authors.initials: GK
authors.lastname: Moates
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Elliston
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
authors.forename: D R
authors.initials: DR
authors.lastname: Wilson
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Coleman
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom. Electronic address: keith.waldron@ifr.ac.uk.
authors.forename: K W
authors.initials: KW
authors.lastname: Waldron
mesh_terms: D029064:Araceae / Q000378:metabolism*; D018533:Biomass; D050260:Carbohydrate Metabolism; D002480:Cellulase / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013227:Steam; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D013227:Steam; D000431:Ethanol; D001617:beta-Glucosidase; D002480:Cellulase
keywords: Bioethanol production; Cellulase; Duckweed; Simultaneous saccharification and fermentation; Steam explosion