Evaluation of evolved xylose fermenting strains for bioethanol production – Comparison of single cells and mixed populations

Conference poster, 2012

Currently large-scale production of bioethanol is mainly based on sugar or starch rich-feedstocks. These raw materials are also employed for animal feed and human use and seem not to be sufficient to the increasing demand. In this context, lignocellulosic raw materials are good alternatives because they do not compete with food crops and are widely distributed. However, its utilization for second generation ethanol production at large-scale still needs improvements. When using lignocellulosic biomass, not only sugars are contained in hydrolysates because toxic compounds derived from cellulose, hemicellulose and lignin degradation during pretreatment are also found in the media. Hence the importance of obtaining robust strains which ferment xylose to ethanol with high yields. In this study, different evolved xylose fermenting Saccharomyces cerevisiae strains were evaluated in ethanol production processes from lignocellulosic hydrolysates. The differences between using lifelines of single cells and mixed populations will also be compared in terms of ethanol production for large scale bioreactors.