D-Xylonate and xylitol as biorefinery products from hemicellulose

The European project BIO-COmmodity REfining - BIOCORE is developing and analysing the industrial feasibility of a biorefinery for conversion of a variety of non-food biomass, including cereal by-products (straws etc.), forestry residues and short rotation woody crops, into 2nd generation biofuel, chemicals and polymers. The key technology in BIOCORE is the organosolv pretreatment with acetic and formic acids, developed by CIMV, which allows extraction of the three major components of biomass; cellulose, hemicelluloses and lignins. In the BIOCORE project, D-xylose in the hemicellulose fraction is converted to xylitol or D-xylonate biotechnically. The production is evaluated through the whole value chain from straw harvesting to the final product. The need for robust, efficient and safe biocatalysts was addressed by engineering an industrial Saccharomyces cerevisiae strain, isolated from spent sulfite liquor and a similarly robust Candida species for xylitol and/or D-xylonate production.