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Updated: May 30, 2026
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Techniques for the Evolution of Robust Pentose-fermenting Yeast for Bioconversion of Lignocellulose to Ethanol
Published on: October 24, 2016
Ethanol production at elevated temperatures using encapsulation of yeast.
Päivi Ylitervo1, Carl Johan Franzén, Mohammad J Taherzadeh
1School of Engineering, University of Borås, 501 90 Borås, Sweden. paivi.ylitervo@hb.se
Journal of Biotechnology
|August 3, 2011
Summary
Encapsulating Saccharomyces cerevisiae improved its heat tolerance, enabling ethanol production at higher temperatures. This macroencapsulation technique enhances yeast performance in fermentation processes.
Area of Science:
- Biotechnology
- Biochemical Engineering
- Microbiology
Background:
- Elevated temperatures pose challenges for yeast fermentation, impacting ethanol production efficiency.
- Saccharomyces cerevisiae, a common industrial yeast, typically exhibits limited thermotolerance.
- Macroencapsulation is a technique used to immobilize microbial cells for industrial applications.
Purpose of the Study:
- To investigate the ethanol production capability of macroencapsulated Saccharomyces cerevisiae CBS 8066 at elevated temperatures.
- To assess the impact of alginate-chitosan encapsulation on yeast thermotolerance and fermentation performance.
- To evaluate the potential of this method for improving simultaneous saccharification and fermentation (SSF) processes.
Main Methods:
- Yeast cells (Saccharomyces cerevisiae CBS 8066) were encapsulated within alginate-chitosan capsules.
- Consecutive batch and continuous cultures were performed at temperatures ranging from 40°C to 45°C.
- Ethanol production and yeast activity were monitored under different temperature regimes and cultivation strategies.
Main Results:
- Encapsulated yeast successfully fermented glucose and produced ethanol at 42°C for five consecutive batches, outperforming free cells.
- Continuous cultivation at 40°C showed high ethanol production for the initial 48 hours with encapsulated cells.
- Encapsulation enhanced the yeast's heat tolerance, allowing short-term ethanol production at temperatures as high as 45°C.
Conclusions:
- Macroencapsulation significantly improves the thermotolerance of Saccharomyces cerevisiae, enabling ethanol production at higher temperatures.
- This enhanced heat tolerance can lead to more efficient bioethanol production, particularly in simultaneous saccharification and fermentation (SSF) processes.
- The alginate-chitosan encapsulation method offers a promising strategy for improving the economic feasibility of industrial bioethanol production.
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