A yeast host cell, which yeast host cell is a Saccharomyces cerevisiae yeast cell, which is capable of producing succinic acid and which comprises - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial external NADH dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 40 or comprising a sequence having at least 90% identity with SEQ ID NO: 40; and - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial external NADH dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 41 or comprising a sequence having at least 90% identity with SEQ ID NO: 41; and - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 42 or comprising a sequence having at least 90% identity with SEQ ID NO: 42; and - at least one genetic modification in its genome resulting in the deficiency of at least one cytosolic glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 57 or comprising a sequence having at least 90% identity with SEQ ID NO: 57; and - at least one genetic modification in its genome resulting in the deficiency of at least one cytosolic glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 58 or comprising a sequence having at least 90% identity with SEQ ID NO: 58; and wherein the host cell overexpresses one or more copies of a nucleic acid encoding a heterologous fumarase and one or more copies of a nucleic acid encoding a fumarate reductase. - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial external NADH dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 40 or comprising a sequence having at least 90% identity with SEQ ID NO: 40; and - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial external NADH dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 41 or comprising a sequence having at least 90% identity with SEQ ID NO: 41; and - a genetic modification in its genome resulting in the deficiency of at least one mitochondrial glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 42 or comprising a sequence having at least 90% identity with SEQ ID NO: 42; and - at least one genetic modification in its genome resulting in the deficiency of at least one cytosolic glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 57 or comprising a sequence having at least 90% identity with SEQ ID NO: 57; and - at least one genetic modification in its genome resulting in the deficiency of at least one cytosolic glycerol-3-phosphate dehydrogenase having an amino acid sequence comprising a sequence as set out in SEQ ID NO: 58 or comprising a sequence having at least 90% identity with SEQ ID NO: 58; and <EOS>