Abstract: The invention relates to a method for propagating yeast, for use in the production of a fermentation product from lignocellulosic biomass, including the steps that consist of: a. providing a reactor; b. placing in contact in said reactor: a population of yeasts capable of metabolising pentoses and hexoses, with 0.2 to 2.0 g of yeast solids per kg of prepared complete medium, raw marc from the pretreatment of the lignocellulosic biomass, with a solids content (MS) of 8% to 15%, nutrients, and cellulases, with 5 to 15 mg of proteins per gram of MS; and c. incubating the mixture at a temperature of 25° C. to 38° C., preferably 28° C. to 33° C., in microaerobiosis, in which the saccharification of the raw marc and the growth of the yeast are carried out simultaneously.

Abstract: The invention relates to a method for propagating yeast, for use in the production of a fermentation product from lignocellulosic biomass, including the steps that consist of: a. providing a reactor; b. placing in contact in said reactor: a population of yeasts capable of metabolising pentoses and hexoses, with 0.2 to 2.0 g of yeast solids per kg of prepared complete medium, raw marc from the pretreatment of the lignocellulosic biomass, with a solids content (MS) of 8% to 15%, nutrients, and cellulases, with 5 to 15 mg of proteins per gram of MS; and c. incubating the mixture at a temperature of 25° C. to 38° C., preferably 28° C. to 33° C., in microaerobiosis, in which the saccharification of the raw marc and the growth of the yeast are carried out simultaneously.

Abstract: The present invention describes a process for the production of alcohol, known as second generation production, from a lignocellulosic substrate, in which a controlled quantity of furfural is produced in situ and which comprises at least the following steps: a first step for alkaline chemical pre-treatment of the substrate; a step for adjusting the pH of the substrate; then a step for enzymatic hydrolysis of said pre-treated substrate; a step for alcoholic fermentation of the hydrolysate obtained with an alcohol-producing microorganism; a step for separation/purification; and a step for acid conversion of at least one liquid fraction into furfural, said liquid fraction being obtained during one of the preceding steps; a step for mixing said furfural obtained with the pre-treated substrate during the pH adjusting step.

Abstract: The present invention describes a process for the production of alcohol, known as second generation production, from a lignocellulosic substrate, in which a controlled quantity of furfural is produced in situ and which comprises at least the following steps: a first step for alkaline chemical pre-treatment of the substrate; a step for adjusting the pH of the substrate; then a step for enzymatic hydrolysis of said pre-treated substrate; a step for alcoholic fermentation of the hydrolysate obtained with an alcohol-producing microorganism; a step for separation/purification; and a step for acid conversion of at least one liquid fraction into furfural, said liquid fraction being obtained during one of the preceding steps; a step for mixing said furfural obtained with the pre-treated substrate during the pH adjusting step.