John McBride

Document Type



The conversion of cellulosic biomass into fuels and chemicals promises to be a major revolution for the United States economy, but is dependent on the advancement of low-cost conversion technology. Of the natural resources available to human societies, biomass is one of the most abundant, and is the sole sustainable source of organic fuels, chemicals, and materials [1]. Biomass derived fuels and chemicals can achieve net zero carbon emissions on a lifecycle basis, provide substantial income to rural communities, and eliminate the security issues associated with fossil resources. Cellulosic biomass (wood, grass, agricultural residues, etc.) can be produced cheaply and converted by chemical or biochemical means into a variety of fuels and chemicals[2]. Arguably the most important advance to be made for biomass conversion is the development of “Consolidated Bioprocessing” (CBP) [3], which refers to converting pretreated biomass into the product of interest in one process step without the addition of cellulase enzymes with either a single organism or a consortium of organisms. Using Saccharomyces cerevisiae as a CBP organism requires the expression of a cellulase system at levels high enough to sustain growth on pretreated biomass. Cellulases release glucose from insoluble cellulose—a major component of biomass—which is consumed for the production of cell mass, carbon dioxide and ethanol by the yeast. Work funded by the Link Foundation Fellowship was, therefore, aimed at the following objectives. 1) Gain understanding of expression levels of cellulases by recombinant S. cerevisiae and the required expression levels for growth on cellulose 2) Understand requirements for selection-based improvement of cellulase expression in liquid culture 3) Design and build optimized constructs for the expression of heterologous cellulase enzymes at the cell surface in S. cerevisiae for use in selection experiments

Publication Date



Link Foundation Fellowship for the years 2004-2006



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