Mechanically robust polysiloxane – ACA capsules for prolonged ethanol production
Journal article, 2013

Background Fermentation using encapsulated yeast leads to more robust ethanol production from lignocellulose hydrolyzates. Encapsulated yeast is much more tolerant to inhibitors present in hydrolyzates, and fermentation is faster due to increased total cell density. For industrial applications, capsules must be made robust enough to endure long periods and numerous cultivations without breaking. Results Liquid core alginatechitosanalginate (ACA) capsules containing Saccharomyces cerevisiae were produced by the liquid-droplet-forming method and treated with hydrolyzed 3-aminopropyltrietoxysilane (hAPTES) forming very glossy capsules. Capsules produced with 3.0% hAPTES showed the best mechanical robustness but no ethanol could be produced in dilute-acid spruce hydrolyzate using these capsules. Untreated ACA capsules gave the highest ethanol production but demonstrated poor mechanical robustness. 25% of the ACA capsules ruptured within 6 h in the shear test. Capsules treated with 1.5% hAPTES were significantly stronger, since only 02% of these capsules broke. Moreover, the ethanol production in the fifth consecutive cultivation in lignocellulose hydrolyzate was nearly as high as for untreated ACA capsules. Conclusion The mechanical robustness of ACA capsules can be easily improved by treating the capsules with hAPTES. ACA capsules treated with 1.5% hAPTES showed excellent mechanical robustness and a similar ethanol production profile to untreated ACA capsules.

3-aminopropyltrietoxysilane

chitosan

alginate

encapsulation

bioethanol production

yeast

robust capsules

Author

Päivi Ylitervo

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Carl Johan Franzén

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Mohammad Taherzadeh Esfahani

University of Borås

Journal of Chemical Technology and Biotechnology

0268-2575 (ISSN) 10974660 (eISSN)

Vol. 88 6 1080-1088

Driving Forces

Sustainable development

Subject Categories

Industrial Biotechnology

DOI

10.1002/jctb.3944

More information

Latest update

11/4/2019