EVALUATION OF EVOLVED AND BARCODED XYLOSE FERMENTING STRAINS FOR BIOETHANOL PRODUCTION FROM LIGNOCELLULOSE
Conference poster, 2012

Lignocellulosic raw materials for bioethanol production are today the basis for many ethanol production sites around the world. However, the utilization of engineered yeast strains for second generation ethanol production at large-scale can still be improved. Yeasts mainly use the sugars present in the lignocellulosic biomass but, toxic compounds derived from cellulose, hemicellulose and lignin degradation during pretreatment are also found in the media and inhibit yeast growth. Furthermore, wild type Saccharomyces cerevisiae is not able to ferment xylose which could constitute up to 40% of the lignocellulose material. Hence the recombinant yeast strains must be robust and ferment xylose to ethanol with high yields in the presence of inhibitors. In this study, different evolved xylose fermenting Saccharomyces cerevisiae strains have been compared in ethanol production processes from lignocellulosic hydrolysates. The differences between using single cell transformants and mixed populations will be evaluated in terms of ethanol production in large scale bioreactors. Furthermore, we have established a method to barcode the evolved yeast strains in order to be able to verify their origin. It is of outmost importance that after barcoding the original characteristics of a yeast strain are maintained. Those requirements can only be fulfilled by using a dominant selection principle. We have obtained a few hundred transformants that were shown to contain the new unique barcode DNA sequence via DNA isolation and DNA sequencing. The transformed strains must be able to grow on the lignocellulosic material and consume xylose at the same rate as before the transformation which also was tested in this study.

Author

Elia Tomas-Pejo

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Nicklas Bonander

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Lisbeth Olsson

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Science and Technology Day 2012, Chalmers University of Technology, 27th March 2012

Subject Categories

Industrial Biotechnology

Bioprocess Technology

Bioenergy

Microbiology

Areas of Advance

Energy

Life Science Engineering (2010-2018)

More information

Created

10/7/2017