Chapter 9 - Expression of Fungal Hydrolases in Saccharomyces cerevisiae

Abstract

Conversion of plant biomass to ethanol or other commodities through direct microbial conversion could be economically feasible if microbes that have optimal processing and product formation properties could be identified or engineered. The yeast Saccharomyces cerevisiae holds several advantages over other candidate organisms for this development, such as its process robustness, long industrial history, and genetic malleability. Because this yeast cannot use polymeric sugar substrates, the heterologous production of the hydrolytic activities required for the degradation of the cellulose and hemicellulose components of plant biomass is imperative. Several researchers have attempted the expression of genes encoding lignocellulolytic hydrolases in S. cerevisiae over the past three decades. This chapter will assess the progress made in this field and will highlight some of the successes and future challenges.