Hydrolysis and fermentation of amorphous cellulose by recombinant Saccharomyces cerevisiae

• Published in: Metabolic engineering 2007, Vol.9 (1), p.87-94
• Main Authors: Den Haan, Riaan, Rose, Shaunita H., Lynd, Lee R., van Zyl, Willem H.
• Format: Article
• Language: English
• Subjects: Base Sequence; Cellulase - genetics; Cellulase expression in yeast; Cellulose - metabolism; Cloning, Molecular; Consolidated bioprocessing; Culture Media; Endoglucanase; Ethanol - metabolism; Fermentation; Hydrolysis; Hypocrea jecorina; Molecular Sequence Data; Recombination, Genetic; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomycopsis fibuligera; Viscosity; β-Glucosidase
• ISSN: 1096-7176; 1096-7184
• DOI: 10.1016/j.ymben.2006.08.005

In this study, we expressed two cellulase encoding genes, an endoglucanase of Trichoderma reesei ( EGI) and the β-glucosidase of Saccharomycopsis fibuligera ( BGL1), in combination in Saccharomyces cerevisiae. The resulting strain was able to grow on phosphoric acid swollen cellulose (PASC) through simultaneous production of sufficient extracellular endoglucanase and β-glucosidase activity. Anaerobic growth (0.03 h −1) up to 0.27 g l −1 DCW was observed on medium containing 10 g l −1 PASC as sole carbohydrate source with concomitant ethanol production of up to 1.0 g l −1. We have thus demonstrated the construction of a yeast strain capable of growth on and one-step conversion of amorphous cellulose to ethanol, representing significant progress towards realization of one-step processing of cellulosic biomass in a consolidated bioprocessing configuration. To our knowledge, this is the first report of a recombinant strain of S. cerevisiae growing on pure cellulose.