Construction of cellobiose-growing and fermenting Saccharomyces cerevisiae strains.

Beta-glucosidase genes of fungal origins were isolated and heterologously expressed in Saccharomyces cerevisiae to enable growth on the disaccharide, cellobiose. To promote secretion of the beta-glucosidases, the genes were fused to the secretion signal of the Trichoderma reesei xyn2 gene and constitutively expressed from a multi-copy yeast expression vector under transcriptional control of the S. cerevisiae PGK1 promoter and terminator.