The effect of pretreatment harshness on separate hydrolysis and fermentation of giant reed by a xylose-consuming Saccharomyces cerevisiae strain
Poster (konferens), 2011

Bioethanol produced from lignocellulosic feedstocks has received increased attention during the last years. To make lignocellulosic biomass susceptible to enzymatic hydrolysis, the materials first have to be pretreated. The pretreatment is often performed under harsh conditions, which release a number of compounds that can be inhibitory for enzymatic hydrolysis and the subsequent fermentation. Xylooligomers and acetic acid are two compounds that are potential inhibitors of enzymatic hydrolysis and fermentation, respectively. The final concentration of these compounds is highly dependent on the pretreatment conditions. In this study, two different pretreatments with different harshness were performed on giant reed. The influence of the resulting material composition on enzymatic hydrolysis was then investigated. The enzymatic hydrolysis was performed at 10 % (w/w) water insoluble solid concentration (WIS) with Celluclast 1.5L and Novozyme 188 with and without the addition of HTec which is acting on hemicellulose. During the harsher pretreatment, more xylooligomers were produced which were found to have a negative effect on the enzymatic hydrolysis. One of the hydrolysates contained a substantially higher concentration of acetic acid. To investigate the effect of this, the hydrolysed giant reed was fermented with a laboratory Saccharomyces cerevisiae strain, VTT C-10880, carrying the XR/XDH pathway. It was found that the acetic acid had a significant negative effect on the xylose consumption. By supplementing the less harsh pretreated material with the same amount of acetic acid, a similar decrease in xylose consumption was observed, indicating that acetic acid is limiting xylose fermentation in this case.

Författare

Magnus Ask

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Kim Olofsson

Diego Gallucci

Laura Ruohonen

Gunnar Lidén

Lisbeth Olsson

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

World Congress on Industrial Biotechnology and Bioprocessing, May 8 - 11, 2011, Toronto, Canada

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Industriell bioteknik

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Energi

Livsvetenskaper och teknik (2010-2018)

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2017-10-07