.3.3. Fermentation
The fermentation was carried out in a 1.5 L bioreactor (Biostat
B plus 8843414 Satorius, Germany) with a working volume of
300 mL. Prior to SSFF, the flocculating yeast strain was aseptically
transferred from the preculture to a sterile YPD medium and cultivated
in 1 L medium up to 4 g/L yeast cells at pH of 5.0, 30 C, agitated
at 90 rpm and aerated with sterile air at 11.2 vvm.
Afterwards, the volume was reduced to 300 mL while the stirrer
was switched off and thus the flocculating yeast culture was concentrated.
The whole SSFF process, consisting of the three integrated
units, was carried out for 96 h.