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Simultaneous saccharification and fermentation of steam-pretreated willow

Eklund, R and Zacchi, Guido LU (1995) In Enzyme and Microbial Technology 17(3). p.255-259
Abstract
Ethanol was produced from SO2-impregnated steam-pretreated willow by simultaneous saccharification and fermentation (SSF). Experiments with SSF were performed in stirred 300-ml vessels and in a 3-1 fermenter. Commercial cellulases were used in combination with either Saccharomyces cerevisiae or Zymomonas mobilis. The amounts of substrate, enzymes, yeast, bacteria, and nutrients were varied. The temperature was maintained at 37 degrees C, and the pH at 5.0. The results indicate that it is possible to reach over 85% of the theoretical ethanol yield, based on the glucan available in the raw material, in 3 days. This was achieved with a substrate concentration of 10% (wt/wt) and a yeast concentration of 10 g l(-1); but even with 1 and 3 g... (More)
Ethanol was produced from SO2-impregnated steam-pretreated willow by simultaneous saccharification and fermentation (SSF). Experiments with SSF were performed in stirred 300-ml vessels and in a 3-1 fermenter. Commercial cellulases were used in combination with either Saccharomyces cerevisiae or Zymomonas mobilis. The amounts of substrate, enzymes, yeast, bacteria, and nutrients were varied. The temperature was maintained at 37 degrees C, and the pH at 5.0. The results indicate that it is possible to reach over 85% of the theoretical ethanol yield, based on the glucan available in the raw material, in 3 days. This was achieved with a substrate concentration of 10% (wt/wt) and a yeast concentration of 10 g l(-1); but even with 1 and 3 g l(-1) yeast, yields of 84.7 and 80%, respectively, were reached. A cellulase concentration corresponding to 18 filter paper U g(-1) substrate was sufficient to complete SSF in 3 days. Zymomonas mobilis gave slightly reduced ethanol yields; however, a reduction in the by-product formation was also obtained compared with the yeast. The nutrient concentration could be considerably reduced compared with literature data without any decrease in the ethanol yield. An increase of substrate concentration from 10 to 15% (wt/wt) reduced the ethanol yield to below 80% as a result of insufficient mass transfer. It was shown that SSF could be performed successfully under nonsterile conditions; however, the substrate and SSF medium must be sterilized prior to SSF. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
SIMULTANEOUS SACCHARIFICATION AND FERMENTATION, ETHANOL FERMENTATION, CELLULOSE HYDROLYSIS
in
Enzyme and Microbial Technology
volume
17
issue
3
pages
255 - 259
publisher
Elsevier
external identifiers
  • wos:A1995QP51300010
  • scopus:0029256762
ISSN
0141-0229
DOI
10.1016/0141-0229(94)00014-I
language
English
LU publication?
yes
id
a24b39c8-61c4-41c0-afb6-e544cb5e5108 (old id 3911549)
date added to LUP
2013-06-28 13:12:06
date last changed
2017-05-28 03:45:27
@article{a24b39c8-61c4-41c0-afb6-e544cb5e5108,
  abstract     = {Ethanol was produced from SO2-impregnated steam-pretreated willow by simultaneous saccharification and fermentation (SSF). Experiments with SSF were performed in stirred 300-ml vessels and in a 3-1 fermenter. Commercial cellulases were used in combination with either Saccharomyces cerevisiae or Zymomonas mobilis. The amounts of substrate, enzymes, yeast, bacteria, and nutrients were varied. The temperature was maintained at 37 degrees C, and the pH at 5.0. The results indicate that it is possible to reach over 85% of the theoretical ethanol yield, based on the glucan available in the raw material, in 3 days. This was achieved with a substrate concentration of 10% (wt/wt) and a yeast concentration of 10 g l(-1); but even with 1 and 3 g l(-1) yeast, yields of 84.7 and 80%, respectively, were reached. A cellulase concentration corresponding to 18 filter paper U g(-1) substrate was sufficient to complete SSF in 3 days. Zymomonas mobilis gave slightly reduced ethanol yields; however, a reduction in the by-product formation was also obtained compared with the yeast. The nutrient concentration could be considerably reduced compared with literature data without any decrease in the ethanol yield. An increase of substrate concentration from 10 to 15% (wt/wt) reduced the ethanol yield to below 80% as a result of insufficient mass transfer. It was shown that SSF could be performed successfully under nonsterile conditions; however, the substrate and SSF medium must be sterilized prior to SSF.},
  author       = {Eklund, R and Zacchi, Guido},
  issn         = {0141-0229},
  keyword      = {SIMULTANEOUS SACCHARIFICATION AND FERMENTATION,ETHANOL FERMENTATION,CELLULOSE HYDROLYSIS},
  language     = {eng},
  number       = {3},
  pages        = {255--259},
  publisher    = {Elsevier},
  series       = {Enzyme and Microbial Technology},
  title        = {Simultaneous saccharification and fermentation of steam-pretreated willow},
  url          = {http://dx.doi.org/10.1016/0141-0229(94)00014-I},
  volume       = {17},
  year         = {1995},
}