Abstract
In this study, we expressed two cellulase encoding genes, an endoglucanase of Trichoderma reesei (EGI) and the b-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 b-glucosidase activity.
Anaerobic growth (0.03 h1
) up to 0.27 g l1 DCW was observed on medium containing 10 g l1 PASC as sole carbohydrate source with
concomitant ethanol production of up to 1.0 g l1
. 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.
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