Engineering the Pichia stipitis genome for fermentation of hemicellulose hydrolysates

Abstract

P. stipitis has been a source of genes for engineering xylose metabolism in Saccharomyces cerevisiae—a task that has been undertaken in numerous laboratories around the world (Jeffries and Jin, 2004). Much less effort has gone into engineering P. stipitis for improved xylose metabolism. In addition to genes for xylose assimilation, P. stipitis possesses the regulatory machinery that enables the efficient conversion of xylose under oxygen limited conditions. While such engineering is conceivable, alteration of transcriptional regulators and cis-acting factors could be very difficult. P. stipitis shunts most of its metabolic flux into ethanol and produces very little xylitol, but its xylose fermentation rate is low relative to that of S. cerevisiae on glucose. Strain development for improved fermentation rates and higher ethanol tolerance is still needed. Increasing the capacity of P. stipitis for rapid xylose fermentation could therefore greatly improve its usefulness in commercial xylose fermentations.

Keywords

Molecular genetics, wood-decaying fungi, microbial metabolism, genetic engineering, alcohol, fungi, industrial applications, biotechnology, yeast fungi, fermentation, yeast, genetics, hydrolysates, xylitol, genomes, hemicellulose, xylose, Pichia stipitis, decay fungi, ethanol

Citation

Jeffries, Thomas W. 2008. Engineering the Pichia stipitis genome for fermentation of hemicellulose hydrolysates. Bioenergy. Washington, D.C. : ASM Press, c2008: pages 37-47.