Hybrid SSF/SHF Processing of SO2 Pretreated Wheat Straw—Tuning Co-fermentation by Yeast Inoculum Size and Hydrolysis Time
(2017) In Applied Biochemistry and Biotechnology 181(2). p.536-547- Abstract
Wheat straw is one of the main agricultural residues of interest for bioethanol production. This work examines conversion of steam-pretreated wheat straw (using SO2 as a catalyst) in a hybrid process consisting of a short enzymatic prehydrolysis step and a subsequent simultaneous saccharification and fermentation (SSF) step with a xylose-fermenting strain of Saccharomyces cerevisiae. A successful process requires a balanced design of reaction time and temperature in the prehydrolysis step and yeast inoculum size and temperature in the SSF step. The pretreated material obtained after steam pretreatment at 210 °C for 5 min using 2.5 % SO2 (based on moisture content) showed a very good enzymatic digestibility at 45 °C... (More)
Wheat straw is one of the main agricultural residues of interest for bioethanol production. This work examines conversion of steam-pretreated wheat straw (using SO2 as a catalyst) in a hybrid process consisting of a short enzymatic prehydrolysis step and a subsequent simultaneous saccharification and fermentation (SSF) step with a xylose-fermenting strain of Saccharomyces cerevisiae. A successful process requires a balanced design of reaction time and temperature in the prehydrolysis step and yeast inoculum size and temperature in the SSF step. The pretreated material obtained after steam pretreatment at 210 °C for 5 min using 2.5 % SO2 (based on moisture content) showed a very good enzymatic digestibility at 45 °C but clearly lower at 30 °C. Furthermore, the pretreatment liquid was found to be rather inhibitory to the yeast, partly due to a furfural content of more than 3 g/L. The effect of varying the yeast inoculum size in this medium was assessed, and at a yeast inoculum size of 4 g/L, a complete conversion of glucose and a 90 % conversion of xylose were obtained within 50 h. An ethanol yield (based on the glucan and xylan in the pretreated material) of 0.39 g/g was achieved for a process with this yeast inoculum size in a hybrid process (10 % water-insoluble solid (WIS)) with 4 h prehydrolysis time and a total process time of 96 h. The obtained xylose conversion was 95 %. A longer prehydrolysis time or a lower yeast inoculum size resulted in incomplete xylose conversion.
(Less)
- author
- Cassells, B. ; Karhumaa, K. LU ; Sànchez I Nogué, V. LU and Lidén, G. LU
- organization
- publishing date
- 2017-02
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Bioethanol, In situ detoxification, SSF, Xylose fermentation, Yeast inoculum size
- in
- Applied Biochemistry and Biotechnology
- volume
- 181
- issue
- 2
- pages
- 536 - 547
- publisher
- Humana Press
- external identifiers
-
- pmid:27631121
- wos:000394219200005
- scopus:84986282077
- ISSN
- 0273-2289
- DOI
- 10.1007/s12010-016-2229-y
- language
- English
- LU publication?
- yes
- id
- 979198b5-499a-4a26-a491-2afa51540e7e
- date added to LUP
- 2016-11-08 08:35:05
- date last changed
- 2024-04-19 12:07:24
@article{979198b5-499a-4a26-a491-2afa51540e7e,
abstract = {{<p>Wheat straw is one of the main agricultural residues of interest for bioethanol production. This work examines conversion of steam-pretreated wheat straw (using SO<sub>2</sub> as a catalyst) in a hybrid process consisting of a short enzymatic prehydrolysis step and a subsequent simultaneous saccharification and fermentation (SSF) step with a xylose-fermenting strain of Saccharomyces cerevisiae. A successful process requires a balanced design of reaction time and temperature in the prehydrolysis step and yeast inoculum size and temperature in the SSF step. The pretreated material obtained after steam pretreatment at 210 °C for 5 min using 2.5 % SO<sub>2</sub> (based on moisture content) showed a very good enzymatic digestibility at 45 °C but clearly lower at 30 °C. Furthermore, the pretreatment liquid was found to be rather inhibitory to the yeast, partly due to a furfural content of more than 3 g/L. The effect of varying the yeast inoculum size in this medium was assessed, and at a yeast inoculum size of 4 g/L, a complete conversion of glucose and a 90 % conversion of xylose were obtained within 50 h. An ethanol yield (based on the glucan and xylan in the pretreated material) of 0.39 g/g was achieved for a process with this yeast inoculum size in a hybrid process (10 % water-insoluble solid (WIS)) with 4 h prehydrolysis time and a total process time of 96 h. The obtained xylose conversion was 95 %. A longer prehydrolysis time or a lower yeast inoculum size resulted in incomplete xylose conversion.</p>}},
author = {{Cassells, B. and Karhumaa, K. and Sànchez I Nogué, V. and Lidén, G.}},
issn = {{0273-2289}},
keywords = {{Bioethanol; In situ detoxification; SSF; Xylose fermentation; Yeast inoculum size}},
language = {{eng}},
number = {{2}},
pages = {{536--547}},
publisher = {{Humana Press}},
series = {{Applied Biochemistry and Biotechnology}},
title = {{Hybrid SSF/SHF Processing of SO<sub>2</sub> Pretreated Wheat Straw—Tuning Co-fermentation by Yeast Inoculum Size and Hydrolysis Time}},
url = {{http://dx.doi.org/10.1007/s12010-016-2229-y}},
doi = {{10.1007/s12010-016-2229-y}},
volume = {{181}},
year = {{2017}},
}