Effect of CUP1 copy number and pH on copper resistance of Saccharomyces cerevisiae enological strains
Jacopo Sica,
Barbara Bovo,
Chiara Nadai,
Milena Carlot,
Alessio Giacomini,
Viviana Corich
Affiliations
Jacopo Sica
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy
Barbara Bovo
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy
Chiara Nadai
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy; Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Viale XXVIII Aprile 14, 31015, Conegliano, TV, Italy; Corresponding author. Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy.
Milena Carlot
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy; Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Viale XXVIII Aprile 14, 31015, Conegliano, TV, Italy
Alessio Giacomini
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy; Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Viale XXVIII Aprile 14, 31015, Conegliano, TV, Italy
Viviana Corich
Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy; Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Viale XXVIII Aprile 14, 31015, Conegliano, TV, Italy; Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, Viale dell’Università 16, 35020, Legnaro, PD, Italy
The widespread use of copper-based pesticides in winemaking can affect wine fermentation. Therefore, it is crucial to assess the resistance levels of Saccharomyces cerevisiae wine strains in enological growth conditions. In the context of winemaking, grape juice is a complex environment capable of chelating copper and is characterized by a distinctly acidic pH. In this work, the effects of copper concentration on the growth of 10 S. cerevisiae strains, isolated from an enological environment, and one commercial starter were tested in YNB minimal medium and synthetic must, mimicking enological conditions.In minimal medium, resistance to copper varied among yeasts (50–600 μM), revealing the presence of three resistance levels (high, intermediate, and low). Representative strains of the three groups were tested at a pH range from 5.2 to 3.0 at the copper concentration that showed a 20–25 % growth reduction. At pH range 5.2–4.5, a growth reduction was observed, while, conversely, a strain-specific recovery was observed at pH range 3.2–3.0.In synthetic must, the strains showed higher copper resistance levels than in minimal medium (50–4000 μM). In both synthetic must and minimal medium, a significant logarithmic correlation was found between copper resistance and CUP1 gene copy number. The copy number tended to better explain resistance in minimal medium compared to synthetic must. The results shed light on the role of CUP1 copy number within an enological environment.
