Abstract: This study evaluated the colonization ability of commercial Saccharomyces cerevisiae RX60 after inoculated into ‘Petit Verdot’ and ‘Marselan’ grapes in 5-ton fermenters, and also investigated the structure of wild yeast populations and the aroma profiles of the resulting wines. The results showed that the colonization ability of RX60 varied significantly among different grape varieties. In ‘Petit Verdot’, RX60 exhibited a strong colonization ability (63.39% at the end of fermentation), while its colonization ability was relatively weak in ‘Marselan’ (only 7.14%). Additionally, the structure of wild yeast populations differed markedly between the two varieties: six genera and ten species of yeast were isolated from ‘Petit Verdot’, including seven genotypes of wild S. cerevisiae; whereas three genera and four species were isolated from ‘Marselan’, with 34 wild S. cerevisiae genotypes. In terms of aroma, the total content of higher alcohols in ‘Marselan’ was 1.36 times that in ‘Petit Verdot’, while the total ester content in ‘Petit Verdot’ was 2.12 times that in ‘Marselan’, primarily characterized by marked accumulation of ethyl hexanoate, ethyl decanoate, and isoamyl acetate. This study demonstrated that the colonization ability of commercial S. cerevisiae was influenced by the wild yeasts present in different grape varieties. Significant competition was observed between commercial and wild yeasts during fermentation, and this competition played a crucial role in shaping the aroma profile and sensory characteristics of wine.

Key words: commercial Saccharomyces cerevisiae; colonization ability; wild yeast; genotyping; aroma; winemaking