Exploring microbial interactions between Saccharomyces cerevisiae and non-Saccharomyces yeast starters in vinification

Abstract

Winemaking is a complex microbial process involving the co-existence and interactions of various microorganisms [1]. Although, commercially available Saccharomyces cerevisiae strains could be inoculated and accomplish a well-controlled must fermentation, the growing recognition of the role of non-Saccharomyces yeasts, increases the interest in using diverse species in mixed inoculated fermentations, where yeast interactions are crucial [2]. The aim of this study was to investigate the microbial interactions between indigenous and commercial S. cerevisiae strains and two commercial and one indigenous non-Saccharomyces species used as fermentation starters under laboratory conditions. The microbial combinations were assessed for their fermentation kinetics and population dynamics. Subsequently, fermentations were conducted using three monovarietal grape musts from Greek varieties, monitoring CO₂ emissions and microbial population dynamics throughout the process [3]. The resulting wines were analyzed for their oenological properties and evaluated through sensory descriptive analysis [4]. Overall, all fermentation were completed successfully. More specifically, sequential inoculation with the first commercial non-Saccharomyces exhibited a significantly lower fermentation rate (~0.4 g/L/h) and rapid population reduction within 24 hours, while the other two strains enhanced fermentation rates and persisted until the completion of the process. Notably, sequential inoculation with the indigenous non-Saccharomyces strain resulted in the predominance of this species (~8.5 log CFU/mL), followed by S. cerevisiae population (~8 log CFU/mL). The second commercial non-Saccharomyces strain exhibited neutral interactions with S. cerevisiae, making it the most promising for further study. Moreover, wines fermented with the latter non-Saccharomyces strain maintained neutral interactions with S. cerevisiae strains and showed no significant differences in oenological properties, including total acidity, volatile acidity, ethanol yield and pH values, compared to those fermented with S. cerevisiae monocultures. Sensory analysis revealed that the inoculation strategy influenced the aromatic profile, with co-inoculated fermentations enhancing floral attributes.

Aknowledgements

The research project entitled «reLees» is implemented in the framework of H.F.R.I call “Basic research Financing (Horizontal support of all Sciences)” under the National Recovery and Resilience Plan “Greece 2.0” funded by the European Union – NextGenerationEU (H.F.R.I. Project Number:15100).

References

[1] Barata, A., Malfeito-Ferreira, M., and Loureiro, V. (2012). International Journal of Food Microbiology 153(3):243–59.

[2] Bordet, F., Joran, A., Klein, G., Roullier-Gall, C., Alexandre, H. (2020). Microorganisms 8(4):1–33.

[3] Renault, P., Coulon, j., de Revel, G., Barbe, J.C., and Bely, M. (2015). International Journal of Food Microbiology, 207:40–48.

[4] Tzamourani, A., Evangelou, A., Ntourtoglou, G., Lytra, G., Paraskevopoulos, I. and Dimopoulou, M. (2024). Applied Sciences, 14(4):1522.