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Designing simultaneous saccharification and fermentation for improved xylose conversion by a recombinant strain of Saccharomyces cerevisiae.

Olofsson, Kim LU ; Rudolf, Andreas LU and Lidén, Gunnar LU (2008) In Journal of Biotechnology 134(1-2). p.112-120
Abstract
Wheat straw is an abundant agricultural residue which can be used as a raw material for bioethanol production. Due to the high xylan content in wheat straw, fermentation of both xylose and glucose is crucial to meet desired overall yields of ethanol. In the present work a recombinant xylose fermenting strain of Saccharomyces cerevisiae, TMB3400, cultivated aerobically on wheat straw hydrolysate, was used in simultaneous saccharification and fermentation (SSF) of steam pretreated wheat straw. The influence of fermentation strategy and temperature was studied in relation to xylose consumption, ethanol formation and by-product formation. In addition, model SSF experiments were made to further investigate the influence of temperature on xylose... (More)
Wheat straw is an abundant agricultural residue which can be used as a raw material for bioethanol production. Due to the high xylan content in wheat straw, fermentation of both xylose and glucose is crucial to meet desired overall yields of ethanol. In the present work a recombinant xylose fermenting strain of Saccharomyces cerevisiae, TMB3400, cultivated aerobically on wheat straw hydrolysate, was used in simultaneous saccharification and fermentation (SSF) of steam pretreated wheat straw. The influence of fermentation strategy and temperature was studied in relation to xylose consumption, ethanol formation and by-product formation. In addition, model SSF experiments were made to further investigate the influence of temperature on xylose fermentation and by-product formation. In particular for SSF at the highest value of fibre content tested (9% water insoluble substance, WIS), it was found that a fed-batch strategy was clearly superior to the batch process in terms of ethanol yield, where the fed-batch gave 71% of the theoretical yield (based on all available sugars) in comparison to merely 59% for the batch. Higher ethanol yields, close to 80%, were obtained at a WIS-content of 7%. Xylose fermentation significantly contributed to the overall ethanol yields. The choice of temperature in the range 30-37 degrees C was found to be important, especially at higher contents of water insoluble solids (WIS). The optimum temperature was found to be 34 degrees C for the raw material and yeast strain studied. Model SSF experiments with defined medium showed strong temperature effects on the xylose uptake rate and xylitol yield. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
SSF, Ethanol, Xylose fermentation, Co-fermentation, Recombinant Saccharomyces cerevisiae, Wheat straw
in
Journal of Biotechnology
volume
134
issue
1-2
pages
112 - 120
publisher
Elsevier
external identifiers
  • pmid:18294716
  • wos:000254681000013
  • scopus:39649107109
ISSN
1873-4863
DOI
10.1016/j.jbiotec.2008.01.004
language
English
LU publication?
yes
id
526a0811-6043-4765-b934-b2e5a35d8e15 (old id 1041587)
date added to LUP
2008-03-25 16:05:40
date last changed
2017-10-01 03:47:29
@article{526a0811-6043-4765-b934-b2e5a35d8e15,
  abstract     = {Wheat straw is an abundant agricultural residue which can be used as a raw material for bioethanol production. Due to the high xylan content in wheat straw, fermentation of both xylose and glucose is crucial to meet desired overall yields of ethanol. In the present work a recombinant xylose fermenting strain of Saccharomyces cerevisiae, TMB3400, cultivated aerobically on wheat straw hydrolysate, was used in simultaneous saccharification and fermentation (SSF) of steam pretreated wheat straw. The influence of fermentation strategy and temperature was studied in relation to xylose consumption, ethanol formation and by-product formation. In addition, model SSF experiments were made to further investigate the influence of temperature on xylose fermentation and by-product formation. In particular for SSF at the highest value of fibre content tested (9% water insoluble substance, WIS), it was found that a fed-batch strategy was clearly superior to the batch process in terms of ethanol yield, where the fed-batch gave 71% of the theoretical yield (based on all available sugars) in comparison to merely 59% for the batch. Higher ethanol yields, close to 80%, were obtained at a WIS-content of 7%. Xylose fermentation significantly contributed to the overall ethanol yields. The choice of temperature in the range 30-37 degrees C was found to be important, especially at higher contents of water insoluble solids (WIS). The optimum temperature was found to be 34 degrees C for the raw material and yeast strain studied. Model SSF experiments with defined medium showed strong temperature effects on the xylose uptake rate and xylitol yield.},
  author       = {Olofsson, Kim and Rudolf, Andreas and Lidén, Gunnar},
  issn         = {1873-4863},
  keyword      = {SSF,Ethanol,Xylose fermentation,Co-fermentation,Recombinant Saccharomyces cerevisiae,Wheat straw},
  language     = {eng},
  number       = {1-2},
  pages        = {112--120},
  publisher    = {Elsevier},
  series       = {Journal of Biotechnology},
  title        = {Designing simultaneous saccharification and fermentation for improved xylose conversion by a recombinant strain of Saccharomyces cerevisiae.},
  url          = {http://dx.doi.org/10.1016/j.jbiotec.2008.01.004},
  volume       = {134},
  year         = {2008},
}