All experiments were carried out in submerged cultures at
30 ◦C, at pH 5.5 in 250 mL Erlenmeyer flasks provided with needlepierced rubber stoppers, which ensured micro-aerobic conditions
and allowed the release of produced carbon dioxide. After each
sampling, nitrogen (0.1 vvm) was flushed in the cultures for 10 min
to assure limited oxygen conditions. At different time intervals,
aliquots were aseptically withdrawn and used for estimation of
ethanol production. Table 1, presents a conclusive list of the con-