Ethanol production at elevated temperatures using encapsulation of yeast
Artikel i vetenskaplig tidskrift, 2011

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.

saccharomyces-cerevisiae cells

simultaneous saccharification

cellulose

Thermotolerance

production

Immobilized cells

Encapsulation

immobilization

thermotolerant

fermentation

environmental-changes

Saccharomyces cerevisiae

Bioethanol

trehalose

technologies

microencapsulation

Författare

Päivi Ylitervo

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Carl Johan Franzén

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Mohammad Taherzadeh Esfahani

Högskolan i Borås

Journal of Biotechnology

0168-1656 (ISSN)

Vol. 156 22-29

Ämneskategorier

Industriell bioteknik

DOI

10.1016/j.jbiotec.2011.07.018