Journal Article

High-level functional expression of a fungal xylose isomerase: the key to efficient ethanolic fermentation of xylose by Saccharomyces cerevisiae?

Jetten, Mike S.M, den Ridder, Jan J.J, Harhangi, Harry R, Winkler, Aaron A, Pronk, Jack T, Stave, Ann Kristin, Op den Camp, Huub J.M, de Laat, Wim T.A.M, Kuyper, Marko, van Dijken, Johannes P

2003

Overview

Evidence is presented that xylose metabolism in the anaerobic cellulolytic fungus Piromyces sp. E2 proceeds via a xylose isomerase rather than via the xylose reductase/xylitol-dehydrogenase pathway found in xylose-metabolising yeasts. The XylA gene encoding the Piromyces xylose isomerase was functionally expressed in Saccharomyces cerevisiae. Heterologous isomerase activities in cell extracts, assayed at 30°C, were 0.3–1.1 μmol min −1 (mg protein) −1, with a K m for xylose of 20 mM. The engineered S. cerevisiae strain grew very slowly on xylose. It co-consumed xylose in aerobic and anaerobic glucose-limited chemostat cultures at rates of 0.33 and 0.73 mmol (g biomass) −1 h −1, respectively.

• Publisher: Elsevier B.V,Blackwell Publishing Ltd,Oxford University Press
• Subject: Aldose-Ketose Isomerases - genetics / Aldose-Ketose Isomerases - metabolism / Anaerobiosis / Bioethanol / Cellulolytic fungi / Ethanol - metabolism / Fermentation / Gene Expression / Hemicellulose / Pentose / Piromyces / Piromyces - enzymology / Piromyces - genetics / Saccharomyces cerevisiae / Saccharomyces cerevisiae - genetics / Saccharomyces cerevisiae - metabolism / XylA gene / Xylitol / Xylose / Xylose - metabolism / Xylose isomerase / Xylose reductase / Yeast