Abstract
The external hydrolysis of polysaccharides is facilitated by the presence of extracellular enzymes. Most strains of Saccharomyces cerevisiae are unable to produce extracellular depolymerizing enzymes that can efficiently liberate fermentable sugars from the vast energy reserves present in starch, cellulose, hemicellulose, and pectin biomass (Figures 23.1-23.4). Commercial enzyme preparations and/or mixed cultures are therefore used in multi-step bioconversions of polysaccharide-rich biomass to yield commercially important commodities. For various reasons, a number of heterologous genes encoding polysaccharidedegrading enzymes (such as amylases, cellulases, xylanases and pectinases) have been expressed in S. cerevisiae to extend the limited range of carbohydrates it can ferment. Before the possible applications of these recombinant strains of S. cerevisiae will be discussed in this chapter, the endogenous amylase, glucanase and pectinase genes of this host organism will be reviewed briefly.
| Original language | English |
|---|---|
| Title of host publication | Yeast sugar metabolism |
| Subtitle of host publication | biochemistry, genetics, biotechnology, and applications |
| Editors | F. K. Zimmermann, K.-D. Entian |
| Place of Publication | Lancaster ; Basel |
| Publisher | Technomic Publishing |
| Pages | 459-501 |
| Number of pages | 43 |
| ISBN (Electronic) | 9781040293928 |
| ISBN (Print) | 9781003578987 |
| DOIs | |
| Publication status | Published - 1997 |
| Externally published | Yes |