Ethanol production by Kluyveromyces marxianus in whey from organic cheese production was examined in batch and continuous mode.
he results showed that no pasteurization or freezing of the whey was necessary and that Kluyveromyces marxianus was able to compete with the lactic acid bacteria added during cheese production. The results also showed that, even though some lactic acid fermentation had taken place prior to ethanol fermentation, Kluyveromyces marxianus was able to take over and produce ethanol from the remaining lactose, since a significant amount of lactic acid was not produced (1–2 g/l). Batch fermentations showed high ethanol yield (*0.50 g ethanol/g lactose) at both 30C and 40C using low pH (4.5) or no pH control.