Exploring non-Saccharomyces wine yeasts native from Castilla-La Mancha (Spain) to enhance bioprotection and quality of wines

Abstract

The current tendency to reduce SO₂ in winemaking, due to its adverse effects in sensitive individuals [1], has led to the development of new techniques to mitigate SO₂ absence and to exert the same antimicrobial and antioxidant effects. Bioprotection is defined as the use of microorganisms or metabolites derived from them for the adequate preservation of food, reducing the use of chemicals [2,3]. Several studies showed the ability of different microorganisms to preserve and improve food quality [3]. More specifically, non-Saccharomyces yeasts have shown numerous positive effects, preserving and improving the organoleptic characteristics of wines [4,5,6].

Thus, this work addressed the isolation and identification of non-Saccharomyces yeasts from different viticultural areas within the Castilla-La Mancha Spanish region, in order to use them as a bioprotection tool in winemaking. Serial dilutions of 27 samples obtained from grapes and musts were seeded onto WL agar plates supplemented with biphenyl (150 mg/L) and chloramphenicol (100 mg/L) and incubated at 25°C for three days.

A total of 214 yeast colonies were isolated and identified to species level by PCR (ITS-5.8S rDNA)-RFLP [7]. Then, one or two isolates of each molecular profile were sequenced using the D1/D2 domains of the 26S region to confirm their identity, obtaining 27 different species of which the most prevalent was Aerobasidium pullulans, followed by Hanseniaspora uvarum, Hanseniaspora guillermondii and Metschnikowia pulcherrima. In addition, other species of interest such as Torulaspora delbrueckii, Lachancea thermotolerans or Pichia kluyveri were also isolated in a minority proportion. The 214 isolates were also evaluated in terms of their acetic acid and hydrogen sulfide production, as well as tolerance to 25 mg/L of SO₂ [8], reducing the number to 39 isolates from 16 different species. Based on these results, these yeasts will be further evaluated depending on their metabolism and possible beneficial effects on wine quality.

References

[1] Lisanti, M. T., Blaiotta, G., Nioi, C., & Moio, L. (2019). Comprehensive Reviews in Food Science and Food Safety, 18(2), 455-479.

[2] Morata, A., Loira, I., González, C., & Escott, C. (2021). Molecules, 2021. 26(15): p. 4571.

[3] Di Gianvito, P., Englezos, V., Rantsiou, K., & Cocolin, L. (2022). International Journal of Food Microbiology, 364, 109532.

[4] Morata, A., Loira, I., Tesfaye, W., Bañuelos, M. A., González, C., & Suárez Lepe, J. A. (2018). Fermentation, 4(3), 53.

[5] Binati, R. L., Junior, W. J. L., Luzzini, G., Slaghenaufi, D., Ugliano, M., & Torriani, S. (2020). International journal of food microbiology, 318, 108470.

[6] Martin, V., Valera, M. J., Medina, K., Boido, E., & Carrau, F. (2018). Fermentation, 4(3), 76

[7] Esteve-Zarzoso, B., et al. (1999). Int J Syst Bacteriol, 49 Pt 1: p. 329‐37.

[8] Caridi, A., et al., (2002). J Gen Appl Microbiol, 48(5): p. 261‐7.