FERMENTATION OF BIOREFINERY STREAMS

Poster (konferens), 2011

Side streams generated from pulping processes have been of interest in the generation of alternative fuels due to the various wood compositional residues such as fermentable sugars leached out with it during the pulping process. These streams, due to their composition of fermentable sugars and other wood carbohydrate residues and the potential to ferment such carbohydrate residues in them for bioethanol production are in that case Biorefinery streams. Although these streams contain several growth inhibitory compounds such as furfural, numerous phenolic derivatives of lignin, several organic acids and are also known to be nutrient- (especially nitrogen-) poor thus constituting a challenging type of substrates for the fermenting microorganism, these traits however make for interesting grey areas for research on cell response to stress . Using biorefinery streams generated by innovative biomass treatments, our project aims at developing robust bioprocessing steps for the production of materials and energy, such as second-generation ethanol by fermentation with Saccharomyces cerevisiae. Fermentability of the substrates generated by the other project partner (Innventia AB) will be investigated, as well as maximum ethanol productivity and yield. The impact of different substrates on yeast metabolism will be investigated. Therefore, part of the research efforts of the project will be dedicated to fundamental studies on the effect of exposure to lignocellulose hydrolysate on energy metabolism, redox power homeostasis, cell integrity and viability. In addition, the effects of nutrient limitations will also be considered.