2.6. Bioreactor assays
Batch cultures were performed in duplicate, using ApplikonMiniBio
bioreactors (250 mL nominal volume), equipped with Peltierrefrigerated
gas condensers. Bioreactors were filled with 150 mL of a
filter-sterilized natural white grape must, mixture of Malvasia and
Viura varieties (260 g/L of sugars), and 200 μL of antifoam204. Temperature
was set to 25 °C, stirring to 1000 rpm and inoculation to 0.2 final
OD600. The cultures were sparged with air 1.2 L/h. CO2 and O2 contents
in the off-gaswere continuously monitoredwith BlueInOne Cell sensors
(Bluesens). Samples were withdrawn after 24 and 48 h for determination
of metabolite concentrations.