Biofuels Production projects
Combinatorial Expression Engineering of Hemicellulose and Pectin Sugar Utilization Pathway
Currently, pectin-rich biomass, such as sugar beet pulp, apple pomace and citrus peels are considered low value waste streams, but these feedstocks can be inexpensively broken down into their component monosaccharides, primarily galacturonic acid (GalA), arabinose, and galactose. The generation of yeast strains with the ability to co-ferment these sugars would allow current waste streams to be converted into a sustainable biofuel. Our specific aims are the following: 1) determine enzyme and metabolite abundances in expression optimized strains enriched in both aerobic and anaerobic growth conditions with proteomics and metabolic flux analysis and use as an improved starting point for strain adaptations. 2) apply our combinatorial expression engineering strategy towards the utilization of galacturonic acid, the primary monosaccharide in pectic polysaccharides. 3) engineer a S.cerevisiae strain capable of co-utilizing galacturonic acid and arabinose.