Enhancement of beta-glucosidase stability and cellobiose-usage using surface-engineered recombinant Saccharomyces cerevisiae in ethanol production

摘要

To enhance the use of cellobiose by a recombinant Sachharomyces cerevisiae, the expressed beta-glucosidase that hydrolyzes cellobiose was stabilized using a surface-display system. The C-terminal half of alpha-agglutinin was used as surface-display motif for the expression of beta-glucosidase in the cell wall. The surface-displayed beta-glucosidase had a half-life time (t(1/2)) of 100 h in acidic culture broth conditions, while secreted beta-glucosidase had a t(1/2) of 60 h. With such stabilization of beta-glucosidase, the surface-engineered S. cerevisiae utilized 7.5 g cellobiose l(-1) over 60 h, while S. cerevisiae secreting beta-glucosidase into culture broth used 5.8 g cellobiose l(-1) over the same period.