This behaviour could support as tentative hypothesis that the increase of peroxides is initially subject to a microbial limitation period, followed by a substrate limitation (i.e. the dissolved oxygen) period where cellular mass is not limiting. Moreover, it is known that S.cerevisiae cell cycle shows a range of doubling times ca. 75–450 min ( Lord and Wheals, 1981 and Tyson et al., 1979) and the ongoing of fermentation is characterised by the presence of subpopulation with respect to intracellular ROS content which content shows an asymmetrical distribution with cell cycles ( Landolfo et al., 2010), and the drop in ROS content from old mothers to daughters cells is due to increased tendency to segregate dysfunctional mitochondria with time ( Lam, Aung-Htut, Lim, Yang, & Dawes, 2011).