Biotechnological phenomics of autochthonous grape yeasts from Douro wine region

Wine typicity, defined by the unique sensory profiles and chemical compositions that are linked to a specific region, is greatly influenced by the “terroir” - a complex interplay of environmental and biological factors in which the microbiota plays a pivotal role. However, the standardization of methods and the usage of commercial microorganisms removed or restricted typicity and regionality in winemaking. Therefore, to regain this lost typicity, this study biochemically characterized 14 native yeast strains, previously isolated by our group from the DOC Douro region. The strains - Saccharomyces cerevisiae , Torulaspora delbrueckii , Lachancea thermotolerans , and Metschnikowia pulcherrima - exhibited diverse stress tolerance profiles, with S. cerevisiae being more tolerant to ethanol and sulphur dioxide, and non- Saccharomyces yeasts showing greater resilience to copper sulphate and osmotic stress. Enzymatic activities varied significantly, with the selected strains demonstrating high β-glycosidase and β-lyase activities. Notably, the low BA production observed, apart from M. pulcherrima , highlights the safety of these yeasts for winemaking. Fermentative performance assessments revealed robust glucose consumption and ethanol production by S. cerevisiae , and medium ethanol production by non- Saccharomyces yeasts. Acetic acid production was significantly variable and glycerol production was low for all the strains. In particular, the isolate SL195 T. delbrueckii produced the highest levels of acetic acid and showed no glycerol production. These findings highlight the potential of native yeasts to preserve and enhance regional wine characteristics, providing an avenue to counteract the increase homogenization of wine profiles in modern viticulture. • Native yeast strains enhance wine typicity and counteract standardization trends. • Technical assessment revealed high stress tolerance and strong enzymatic activity. • Non- Saccharomyces yeast showed high β-glycosidase and β-lyase activities for aroma. • Fermentation highlights distinct ethanol, acetic acid, and glycerol production. • Findings support the potential of using native microbiota to restore wine typicity.