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Ethanol production at elevated temperatures using encapsulation of yeast

Päivi Ylitervo (Institutionen för kemi- och bioteknik, Industriell Bioteknik ) ; Carl Johan Franzén (Institutionen för kemi- och bioteknik, Industriell Bioteknik ) ; M. J. Taherzadeh
Journal of Biotechnology (0168-1656). Vol. 156 (2011), 1, p. 22-29.
[Artikel, refereegranskad vetenskaplig]

The ability of macroencapsulated Saccharomyces cerevisiae CBS 8066 to produce ethanol at elevated temperatures was investigated in consecutive batch and continuous cultures. Prior to cultivation yeast was confined inside alginate-chitosan capsules composed of an outer semi-permeable membrane and an inner liquid core. The encapsulated yeast could successfully ferment 30 g/L glucose and produce ethanol at a high yield in five consecutive batches of 12 h duration at 42 degrees C, while freely suspended yeast was completely inactive already in the third batch. A high ethanol production was observed also through the first 48 h at 40 degrees C during continuous cultivation at D = 0.2 h(-1) when using encapsulated cells. The ethanol production slowly decreased in the following days at 40 degrees C. The ethanol production was also measured in a continuous cultivation in which the temperature was periodically increased to 42-45 degrees C and lowered to 37 degrees C again in periods of 12 h. Our investigation shows that a non-thermotolerant yeast strain improved its heat tolerance upon encapsulation, and could produce ethanol at temperatures as high as 45 degrees C for a short time. The possibility of performing fermentations at higher temperatures would greatly improve the enzymatic hydrolysis in simultaneous saccharification and fermentation (SSF) processes and thereby make the bioethanol production process more economically feasible.

Nyckelord: Encapsulation, Immobilized cells, Saccharomyces cerevisiae, Bioethanol, production, Thermotolerance, saccharomyces-cerevisiae cells, simultaneous saccharification, environmental-changes, fermentation, microencapsulation, thermotolerant, trehalose, cellulose, immobilization, technologies



Denna post skapades 2011-11-10. Senast ändrad 2014-09-02.
CPL Pubid: 148346

 

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Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Industriell Bioteknik (2008-2014)

Ämnesområden

Industriell bioteknik

Chalmers infrastruktur

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