Improving simultaneous saccharification and co-fermentation of pretreated wheat straw using both enzyme and substrate feeding.
(2010) In Biotechnology for Biofuels 3.- Abstract
- ABSTRACT: BACKGROUND: Simultaneous saccharification and co-fermentation (SSCF) has been recognized as a feasible option for ethanol production from xylose-rich lignocellulosic materials. To reach high ethanol concentration in the broth, a high content of water-insoluble solids (WIS) is needed, which creates mixing problems and, furthermore, may decrease xylose uptake. Feeding of substrate has already been proven to give a higher xylose conversion than a batch SSCF. In the current work, enzyme feeding, in addition to substrate feeding, was investigated as a means of enabling a higher WIS content with a high xylose conversion in SSCF of a xylose-rich material. A recombinant xylose-fermenting strain of Saccharomyces cerevisiae (TMB3400) was... (More)
- ABSTRACT: BACKGROUND: Simultaneous saccharification and co-fermentation (SSCF) has been recognized as a feasible option for ethanol production from xylose-rich lignocellulosic materials. To reach high ethanol concentration in the broth, a high content of water-insoluble solids (WIS) is needed, which creates mixing problems and, furthermore, may decrease xylose uptake. Feeding of substrate has already been proven to give a higher xylose conversion than a batch SSCF. In the current work, enzyme feeding, in addition to substrate feeding, was investigated as a means of enabling a higher WIS content with a high xylose conversion in SSCF of a xylose-rich material. A recombinant xylose-fermenting strain of Saccharomyces cerevisiae (TMB3400) was used for this purpose in fed-batch SSCF experiments of steam-pretreated wheat straw. RESULTS: By using both enzyme and substrate feeding, the xylose conversion in SSCF could be increased from 40% to 50% in comparison to substrate feeding only. In addition, by this design of the feeding strategy, it was possible to process a WIS content corresponding to 11% in SSCF and obtain an ethanol yield on fermentable sugars of 0.35 g g-1. CONCLUSION: A combination of enzyme and substrate feeding was shown to enhance xylose uptake by yeast and increase overall ethanol yield in SSCF. This is conceptually important for the design of novel SSCF processes aiming at high-ethanol titers. Substrate feeding prevents viscosity from becoming too high and thereby allows a higher total amount of WIS to be added in the process. The enzyme feeding, furthermore, enables keeping the glucose concentration low, which kinetically favors xylose uptake and results in a higher xylose conversion. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1665714
- author
- Olofsson, Kim LU ; Palmqvist, Benny LU and Lidén, Gunnar LU
- organization
- publishing date
- 2010
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Biotechnology for Biofuels
- volume
- 3
- article number
- 17
- publisher
- BioMed Central (BMC)
- external identifiers
-
- wos:000281433100001
- pmid:20678195
- scopus:77955061349
- pmid:20678195
- ISSN
- 1754-6834
- DOI
- 10.1186/1754-6834-3-17
- language
- English
- LU publication?
- yes
- id
- d5d29a92-cd76-4155-ab85-e52170a53753 (old id 1665714)
- date added to LUP
- 2016-04-01 14:40:33
- date last changed
- 2023-12-12 08:32:40
@article{d5d29a92-cd76-4155-ab85-e52170a53753, abstract = {{ABSTRACT: BACKGROUND: Simultaneous saccharification and co-fermentation (SSCF) has been recognized as a feasible option for ethanol production from xylose-rich lignocellulosic materials. To reach high ethanol concentration in the broth, a high content of water-insoluble solids (WIS) is needed, which creates mixing problems and, furthermore, may decrease xylose uptake. Feeding of substrate has already been proven to give a higher xylose conversion than a batch SSCF. In the current work, enzyme feeding, in addition to substrate feeding, was investigated as a means of enabling a higher WIS content with a high xylose conversion in SSCF of a xylose-rich material. A recombinant xylose-fermenting strain of Saccharomyces cerevisiae (TMB3400) was used for this purpose in fed-batch SSCF experiments of steam-pretreated wheat straw. RESULTS: By using both enzyme and substrate feeding, the xylose conversion in SSCF could be increased from 40% to 50% in comparison to substrate feeding only. In addition, by this design of the feeding strategy, it was possible to process a WIS content corresponding to 11% in SSCF and obtain an ethanol yield on fermentable sugars of 0.35 g g-1. CONCLUSION: A combination of enzyme and substrate feeding was shown to enhance xylose uptake by yeast and increase overall ethanol yield in SSCF. This is conceptually important for the design of novel SSCF processes aiming at high-ethanol titers. Substrate feeding prevents viscosity from becoming too high and thereby allows a higher total amount of WIS to be added in the process. The enzyme feeding, furthermore, enables keeping the glucose concentration low, which kinetically favors xylose uptake and results in a higher xylose conversion.}}, author = {{Olofsson, Kim and Palmqvist, Benny and Lidén, Gunnar}}, issn = {{1754-6834}}, language = {{eng}}, publisher = {{BioMed Central (BMC)}}, series = {{Biotechnology for Biofuels}}, title = {{Improving simultaneous saccharification and co-fermentation of pretreated wheat straw using both enzyme and substrate feeding.}}, url = {{http://dx.doi.org/10.1186/1754-6834-3-17}}, doi = {{10.1186/1754-6834-3-17}}, volume = {{3}}, year = {{2010}}, }