## 3 Results and Discussion
### Fermentation Kinetics
bailii_ grew without problem in the M2 medium without reaching the stationary phase. During this co-culture, _T. delbrueckii_ reached the exponential growth phase at 12 h, showing a very slight loss of viability from this incubation time. Lastly, the ternary co-culture is depicted in Figure 3D. It displays the growth kinetics of _S. cerevisiae_ and _Z. bulli_, similar to those of the other co-cultures in this medium. Conversely, _T. delbrueckii_ competed well with the other two yeasts for up to 12 h of incubation during the ternary co-culture. Then, it showed an even more pronounced loss of viability than in the Sc/Td co-culture, where no viability was detected at 24 h.  
Table 2 presents the fermentation parameters of the cultures in the M2 medium. Similar to the YPD medium cultures, the \(\mu\) values in Table 2 show no significant differences (\(p>0.05\)), indicating a consistent initial growth pattern for the different yeasts. This agrees with that reported previously by [PERSON] et al. [41], who found that 70% of the co-cultures of 15 yeasts did not show changes in \(\mu\) values. However, as the exponential growth phase approaches its end, nutrient depletion becomes apparent, exposing some particular differences in yeast growth, as shown by the kinetics in Figure 3.  
This table also shows that all cultures only partially consumed the sugars in the M2 medium. However, a better consumption of glucose was observed compared to fructose. Glucose consumption was between 56.5% (Td/Zb co-culture) and 96.4% (Sc/Zb co-culture). In comparison, fructose consumption ranged from 22.1% (Td monoculture) to 50.3% (Zb monoculture). Regarding ethanol production, the highest concentrations were produced by the cultures where _S. cerevisiae_ was present: monoculture, Sc/Zb co-culture, and ternary culture. Considering the high capacity of _S. cerevisiae_ to produce ethanol, it is noticeable that the Sc/Td culture produced the lowest ethanol concentration. The highest value of _Y\({}_{P/S}\)_ was obtained by the Td/Zb co-culture, which presented intermedium ethanol production but the lowest sugar consumption. The growth kinetics of the monocultures in both media are shown in Supplementary Figure S1. This figure shows that _Z. bailii_ grows similarly in both media during 24 h of incubation. On the other hand, the growth of _S. cerevisiae_ and _T. delbrueckii_ in the M2 medium was similar to that in the YPD medium only up to 9-12 h of culture. Afterward, _S. cerevisiae_ showed a slight loss of viability, while _T. delbrueckii_ entered the stationary phase. Therefore, the loss of viability of _T. delbrueckii_ observed in M2 medium in co-cultures with _S. cerevisiae_ is due to the interaction with the latter yeast; the low nutritional quality of the M2 medium certainly influences but is not the main reason for, the population decline of _T. delbrueckii_. Actually, the survival of _S. cerevisiae_ in the M2 medium is better in co-cultures than in its monoculture. This suggests that interaction with non-_Saccharomycesyeas activates physiological responses in _S. cerevisiae_, increasing its ability to compete and survive in nutritionally poor media. However, this is a matter for future research. Lastly, all the tests reported here were carried out with one strain of each yeast species. Thus, some variation in the response would be expected from other strains of _T. delbrueckii_, _Z. bailii_, and _S. cerevisiae_.