Metabolic and molecular adaptation of wine yeasts at low temperature fermentation: strategies for their genetic improvement
Low temperature alcoholic fermentations are becoming more frequent as they enhance wine’s aromatic profile but present some disadvantages: reduced growth rate, long lag phase, sluggish or stuck fermentations. We compared the metabolome of wine yeast growing at 12 ºC and 28 ºC in a synthetic must. Th...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2013 |
| Country: | España |
| Institution: | Universitat Rovira i virgili (URV) |
| Repository: | Repositori Institucional de la Universitat Rovira i Virgili |
| OAI Identifier: | oai:urv.cat:TDX:1226 |
| Online Access: | https://hdl.handle.net/20.500.11797/TDX1226 http://hdl.handle.net/10803/123828 |
| Access Level: | Open access |
| Keyword: | 663/664 - Aliments i nutrició. Enologia. Olis. Greixos 579 - Microbiologia 577 - Bioquímica. Biologia molecular. Biofísica 57 - Biologia |
| Summary: | Low temperature alcoholic fermentations are becoming more frequent as they enhance wine’s aromatic profile but present some disadvantages: reduced growth rate, long lag phase, sluggish or stuck fermentations. We compared the metabolome of wine yeast growing at 12 ºC and 28 ºC in a synthetic must. The main differences were observed in lipid metabolism and redox homeostasis. We also compared the metabolome of the cryotolerant yeasts, Saccharomyces bayanus var. uvarum and Saccharomyces kudriavzevii, growing at 12 ºC to the metabolome of S. cerevisiae. The main differences were found for fructose metabolism. We also analyzed the growth and fermentation capacity of lipid mutants and overexpressing strains. The increase in gene-dosage of PSD1, LCB3 and OLE1 genes improved both growth and fermentation activity. Finally, we developed cold adapted wine yeast strains by evolutionary engineering, and deciphered the underlying changes, resulting in new strain with up-regulation of 4 genes belonging to DAN/TIR family. |
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