Indigenous Yeasts from a Maceratino Vineyard: Sequential Fermentation as a Strategy to Enhance Wine Complexity.

Abstract

This study investigated indigenous yeasts associated with the autochthonous Maceratino grape variety (central Italy) evaluating a selection of isolates for their oenological potential and subsequent sequential fermentation trials. A total of 163 yeast isolates were collected using direct and auto-enrichment methods, of which 35 were identified with molecular methods and 16 representative strains were characterized for their oenological properties. Indigenous Saccharomyces cerevisiae strains showed fermentation performances comparable to commercial starters, whereas non-Saccharomyces species exhibited complementary technological traits despite their limited fermentative capacity. Based on the overall screening, 4 indigenous strains were selected for pure and sequential fermentation trials: S. cerevisiae DiSVA 898 in pure and sequential fermentation with Metschnikowia pulcherrima DiSVA 875, Hanseniaspora opuntiae DiSVA 883 and Lachancea thermotolerans DiSVA 890. Sequential inoculations generated wines with distinct volatile and sensory characteristics, each exhibiting a unique aromatic profile. Notably, the sequential fermentation strategy involving L. thermotolerans DiSVA 890 provided significant biological acidification, producing 2.16 g/L of lactic acid and an enhancement of isoamyl acetate and β-phenyl ethanol, while the sequential inoculation workflow with M. pulcherrima DiSVA 875 enhanced higher alcohol and ester concentrations. Overall, the results show that S. cerevisiae and non-Saccharomyces indigenous yeasts represent a valuable source for developing mixed starter cultures offering preliminary insights into the physiological potential of local isolates to modulate the analytical and sensory profile of Maceratino wine.