TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The cell further comprises: a genetic modification comprising a genetic modification that increases the specific activity of dihydroxyacetone kinase, a genetic modification that increases transport of glycerol into the cell, an exogenous gene coding for an enzyme for activation of the pyruvate formate lyase, a genetic modification that increases the specific acetyl-CoA synthetase activity in the cell, and a genetic modification that reduces specific NAD+-dependent glycerol 3-phosphate dehydrogenase activity in the cell, while the yeast cell comprises a functional high osmolarity glycerol response pathway; and at least one of an exogenous xylose isomerase gene, which gene confers to the cell the ability to isomerise xylose into xylulose, and an exogenous genes coding for a L-arabinose isomerase, a L-ribulokinase and a L-ribulose-5-phosphate 4-epimerase, which genes together confer to the cell the ability to convert L-arabinose into D-xylulose 5-phosphate. In the yeast cell, at least one of: (a) the genetic modification that reduces specific NAD+ -dependent formate dehydrogenase activity in the cell comprises the inactivation of at least one endogenous copy of a gene encoding a formate dehydrogenase in the cell's genome; (b) the genetic modification that increases the specific activity of the NAD+-linked glycerol dehydrogenase is expression of a heterologous gene encoding an NAD+-linked glycerol dehydrogenase; (c) the genetic modification that increases transport of glycerol into the cell is overexpression of a nucleotide sequence encoding at least one of a glycerol uptake protein and a glycerol channel; (d) the genetic modification that reduces specific NAD+-dependent glycerol 3-phosphate dehydrogenase activity in the cell comprises the inactivation of at least one endogenous copy of a gene encoding a glycerol 3-phosphate dehydrogenase in the cell's genome; (e) the genetic modification that increases the specific acetyl-CoA synthetase activity is overexpression of a nucleotide sequence encoding an acetyl-CoA synthetase; and (f) the genetic modification that increases the specific activity of dihydroxyacetone kinase is overexpression of a nucleotide sequence encoding a dihydroxyacetone kinase. In the yeast cell, where: (a) the exogenous gene coding for an enzyme with pyruvate formate lyase activity comprises a nucleotide sequence coding for an amino acid sequence with at least 57% amino acid sequence identity with SEQ ID No. 1; (b) the exogenous gene coding for the pyruvate formate lyase activating enzyme comprises a nucleotide sequence coding for an amino acid sequence with at least 70% amino acid sequence identity with SEQ ID No. 3; (c) the gene encoding a formate dehydrogenase whose activity is to be reduced or inactivated in the cell of the invention is a gene encoding a formate dehydrogenase having an amino acid sequence with at least 70% sequence identity to at least one of SEQ ID No. 5 and 6; (d) the exogenous gene coding for the enzyme with acetaldehyde dehydrogenase activity comprises a nucleotide sequence coding for an amino acid sequence with at least one of (i) at least 64% amino acid sequence identity with SEQ ID No. 7, (ii) at least 76% amino acid sequence identity with SEQ ID No. 9 and (iii) at least 61% amino acid sequence identity with SEQ ID No. 11; (e) the nucleotide sequence encoding the NAD+-linked glycerol dehydrogenase comprises a nucleotide sequence coding for an amino acid sequence with at least 50% amino acid sequence identity with SEQ ID No. 49; (f) the nucleotide sequence encoding the dihydroxyacetone kinase comprises a nucleotide sequence coding for an amino acid sequence with at least 50% amino acid sequence identity with at least one of SEQ ID No. 14, 15 and 52; (g) the nucleotide sequence encoding the glycerol uptake protein comprises a nucleotide sequence coding for an amino acid sequence with at least 50% amino acid sequence identity with at least one of SEQ ID No. 16 and 17, where the nucleotide sequence encoding the glycerol channel comprises a nucleotide sequence coding for an amino acid sequence with at least 30% amino acid sequence identity with the amino acid sequence between amino acids 250 and 530 of SEQ ID No. 18; (h) the nucleotide sequence encoding the acetyl-CoA synthetase comprises an amino acid sequence with at least 70% amino acid sequence identity with at least one of SEQ ID No. 19 and 20; and (i) the gene encoding a glycerolphosphate dehydrogenase whose activity is to be reduced or inactivated in the cell of the invention is a gene encoding a glycerolphosphate dehydrogenase having an amino acid sequence with at least 70% sequence identity to SEQ ID No. 21, while the cell has at least one functional copy of a endogenous gene encoding a glycerolphosphate dehydrogenase having an amino acid sequence with at least 70% sequence identity to SEQ ID No. 22, where sequences not defined here may be found at ftp://ftp.wipo.int/pub/published-pct-sequences/publication. The yeast cell comprises at least one further genetic modification comprising increased xylulose kinase specific activity, increased flux of the pentose phosphate pathway, reduced unspecific aldose reductase specific activity, increased transport of at least one of xylose and arabinose into the host cell, decreased sensitivity to catabolite repression, increased tolerance to ethanol, osmolarity or organic acids, and reduced production of by-products. The yeast cell is of a genus comprising Saccharomyces, Kluyveromyces, Candida, Pichia, Schizosaccharomyces, Hansenula, Kloeckera, Schwanniomyces, and Yarrowia. The yeast cell belongs to a species comprising Saccharomyces cerevisiae, Saccharomyces exiguus, S. bayanus , Kluyveromyces lactis, Kluyveromyces marxianus and Schizosaccharomyces pombe. In the yeast cell, at least one of the nucleotide sequences coding for the enzyme with pyruvate formate lyase activity, the pyruvate formate lyase activating enzyme, the enzyme with acetaldehyde dehydrogenase activity, where the xylose isomerase, the L-arabinose isomerase, the L- ribulokinase and the L-ribulose-5-phosphate 4-epimerase is a nucleotide sequence the codon usage of which has been optimized for expression in the yeast cell.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The fermentation product is ethanol. The medium contains or is fed with a lignocellulosic hydrolysate. The yeast cell ferments under anaerobic conditions. The pH of the medium is regulated during the fermentation process to maintain a concentration of undissociated formic acid that is not higher than 20 mM. EXAMPLE - No suitable example given.