Abstract: The invention relates to a method for selecting a yeast strain having improved capability for fermenting a pentose, advantageously xylose, in the presence of organic acid, advantageously acetic acid, in non-dissociated form, in which at least one yeast strain that is capable of fermenting said pentose is consecutively cultured in the following two media: a first growth medium comprising said pentose as the only carbon source and said organic acid in non-dissociated form; a second growth medium comprising another carbon source as the only carbon source, advantageously glucose, free of said organic acid in non-dissociated form, the consecutive culture in at least said two growth media being repeated at least twice, in the presence of rising concentrations of organic acid in non-dissociated form.

Abstract: The present application relates to improved Saccharomyces cerevisiae yeast strains that co-express a gene encoding a glucoamylase of fungal origin and a gene encoding the glucoamylase of Saccharomyces cerevisiae var. diastaticus. The present invention also relates to a method for obtaining these yeast strains involving a) genetically modifying a Saccharomyces cerevisiae yeast to co-express a gene encoding a glucoamylase of fungal origin and a gene encoding the glucoamylase of Saccharomyces cerevisiae var. diastaticus; b) culturing and fermenting the strain obtained in step a) on a dextrin medium; c) selecting the strains having fermentation kinetics at least equal to or greater than those obtained with the strain deposited at the CNCM [French National Collection of Microorganism Cultures] under number I 4999 under the same conditions. The yeast strains according to the invention are of particular interest in producing bioethanol.

Abstract: The invention relates to a method for selecting a yeast strain having improved capability for fermenting a pentose, advantageously xylose, in the presence of organic acid, advantageously acetic acid, in non-dissociated form, in which at least one yeast strain that is capable of fermenting said pentose is consecutively cultured in the following two media: a first growth medium comprising said pentose as the only carbon source and said organic acid in non-dissociated form; a second growth medium comprising another carbon source as the only carbon source, advantageously glucose, free of said organic acid in non-dissociated form, the consecutive culture in at least said two growth media being repeated at least twice, in the presence of rising concentrations of organic acid in non-dissociated form.

Abstract: The invention relates to a method for selecting a yeast strain having improved capability for fermenting a pentose, advantageously xylose, in the presence of organic acid, advantageously acetic acid, in non-dissociated form, in which at least one yeast strain that is capable of fermenting said pentose is consecutively cultured in the following two media: a first growth medium comprising said pentose as the only carbon source and said organic acid in non-dissociated form; a second growth medium comprising another carbon source as the only carbon source, advantageously glucose, free of said organic acid in non-dissociated form, the consecutive culture in at least said two growth media being repeated at least twice, in the presence of rising concentrations of organic acid in non-dissociated form.

Abstract: The present application relates to improved Saccharomyces cerevisiae yeast strains that co-express a gene encoding a glucoamylase of fungal origin and a gene encoding the glucoamylase of Saccharomyces cerevisiae var. diastaticus. The present invention also relates to a method for obtaining these yeast strains involving a) genetically modifying a Saccharomyces cerevisiae yeast to co-express a gene encoding a glucoamylase of fungal origin and a gene encoding the glucoamylase of Saccharomyces cerevisiae var. diastaticus; b) culturing and fermenting the strain obtained in step a) on a dextrin medium; c) selecting the strains having fermentation kinetics at least equal to or greater than those obtained with the strain deposited at the CNCM [French National Collection of Microorganism Cultures] under number I 4999 under the same conditions. The yeast strains according to the invention are of particular interest in producing bioethanol.

Abstract: The present invention concerns yeast strains that have improved properties relative to the specialized strains that are used in the production of first-generation ethanol. In particular, the strains of the invention have an increased ethanol yield, a lower production of glycerol and ethanol production kinetics that are similar or slightly slower than standard strain D1B. The present invention also concerns the yeasts obtained by culturing said strains, and the use of said yeasts and/or of said strains in the industrial production of ethanol.

Abstract: The invention relates to a method for selecting a yeast strain having improved capability for fermenting a pentose, advantageously xylose, in the presence of organic acid, advantageously acetic acid, in non-dissociated form, in which at least one yeast strain that is capable of fermenting said pentose is consecutively cultured in the following two media: a first growth medium comprising said pentose as the only carbon source and said organic acid in non-dissociated form; a second growth medium comprising another carbon source as the only carbon source, advantageously glucose, free of said organic acid in non-dissociated form, the consecutive culture in at least said two growth media being repeated at least twice, in the presence of rising concentrations of organic acid in non-dissociated form.

Abstract: The present invention concerns yeast strains that have improved properties relative to the specialised strains that are used in the production of first-generation ethanol. In particular, the strains of the invention have an increased ethanol yield, a lower production of glycerol and ethanol production kinetics that are similar or slightly slower than standard strain D1B. The present invention also concerns the yeasts obtained by culturing said strains, and the use of said yeasts and/or of said strains in the industrial production of ethanol.

Abstract: The present invention relates to the field of methods for obtaining ethanol-producing yeast strains, to the field of the thus produced strains and to the field of the industrial production of ethanol from said strains. Particularly, the present invention relates, in the most general aspect thereof, to a method for preparing yeasts from industrial Saccharomyces cerevisiae strains, to said strains, and to the use thereof in the industrial production of ethanol from industrial media containing at least one pentose.

Abstract: The present invention relates to novel yeast strains intended for alcohol production. The present invention also relates to yeasts obtained by cultures of said yeast strains and use thereof for producing alcohol, in particular in a toxic fermentation medium. Another object of the invention relates to a method of selecting yeast strains that are resistant to a toxic fermentation medium.

Abstract: The present invention relates to the field of methods for obtaining ethanol-producing yeast strains, to the field of the thus produced strains and to the field of the industrial production of ethanol from said strains. Particularly, the present invention relates, in the most general aspect thereof, to a method for preparing yeasts from industrial Saccharomyces cerevisiae strains, to said strains, and to the use thereof in the industrial production of ehtanol from industrial media containing at least one pentose.

Abstract: The present invention relates to novel yeast strains intended for alcohol production. The present invention also relates to yeasts obtained by cultures of said yeast strains and use thereof for producing alcohol, in particular in a toxic fermentation medium. Another object of the invention relates to a method of selecting yeast strains that are resistant to a toxic fermentation medium.