The accumulation of succinate by the yeast Brettanomyces bruxellensis

The metabolism of Brettanomyces bruxellensis was investigated to determine the metabolic block responsible for the accumulation of acetate seen in cultures of this yeast. In glucose-grown cultures the major non-volatile intracellular organic acide was succinic acid. These cultures also had low levels of succinic dehydrogenase (succinate dehydrogenase, EC 1.3.99.1) and did not produce CO2 from the carbons of ethanol. It was concluded that a block in the oxidation of ethanol occurred at the level of succinic dehydrogenase. If glucose-grown cultures were transferred to ethanol medium, the block in the metabolism of ethanol was partially overcome; the level of succinic dehydrogenase increased, the concentration of the intracellular succinate decreased, and CO2 could be produced from C-1 of ethanol.