title: Fermentation of cellobiose to ethanol by industrial Saccharomyces strains carrying the β-glucosidase gene (BGL1) from Saccharomycopsis fibuligera.
abstract: Constructs carrying the Saccharomycopsis fibuligera β-glucosidase gene (BGL1) under the control of a constitutive actin or a galactose-inducible promoter were introduced into eleven Saccharomyces strains. In ten of these recombinant strains, BGL1 expression driven by the actin promoter was between 1.6- and 18-fold higher than that obtained with the galactose-inducible promoter. Strains carrying the actin promoter yielded ethanol concentrations from cellobiose of between 0.5% and 14%, depending on their ability to accumulate Bgl1 (between 30 and 250 mU/mL) but also on their genetic background. Comparative analysis of a S. cerevisiae strain and its corresponding petite version showed similar ethanol yields, despite a 3-fold lower β-glucosidase production of the latter, suggesting that respiratory activity could be one of the factors influencing ethanol production when using carbon sources other than glucose. This study provides a selection of strains that may be good candidates as hosts for ethanol biosynthesis from cellulosic substrates.
authors.affiliation: Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, CSIC, Paterna, Valencia, Spain.
authors.forename: Leontina
authors.initials: L
authors.lastname: Gurgu
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Lafraya
authors.forename: Julio
authors.initials: J
authors.lastname: Polaina
authors.forename: Julia
authors.initials: J
authors.lastname: Marín-Navarro
mesh_terms: D001483:Base Sequence; D002448:Cell Adhesion; D002475:Cellobiose / Q000378:metabolism*; D017931:DNA Primers; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005966:Glucuronidase / Q000235:genetics*; D006031:Glycosylation; D012440:Saccharomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D002475:Cellobiose; D000431:Ethanol; D005966:Glucuronidase