Concerning future process optimization, the main conclusions
of this work would be that increasing oxygen supply (up to the
upper levels assayed in this work) would positively contribute to
alcohol level reduction and Efficacy of the process (despite the
negative impact on acetic acid yields). In addition, C. sake CBS 5093
appears as the most promising strain among those tested. Using
C. sake for alcohol level reduction by respiration would avoid most
of the problems associated to volatile acidity (Fig. 1C), while alcohol
level reduction and Efficacy would be high. According to Table 2,
optimal conditions for this strain would probably involve initial
YAN close to 150 mg N/L, 25 C, and high oxygenation levels.