Abstract: To investigate indigenous yeast resources and diversity in the wine producing region of Penglai, Shandong, WLN medium combined with sequencing of the D1/D2 region of the 26S rDNA was employed to isolate and identify yeasts during spontaneous fermentation of four wine grape cultivars (Chardonnay, Petit Manseng, Petit Verdot and Marselan). A total of 1 090 yeast strains, spanning 18 species across 11 genera, were isolated. Petit Manseng demonstrated the lowest yeast diversity, and red grape cultivars displayed higher yeast diversity than did white grape cultivars. The typical yeast compositions at different fermentation stages exhibited both shared and distinct characteristics among grape cultivars. Saccharomyces cerevisiae, Hanseniaspora uvarum, H. vineae, and Starmerella bacillaris were identified as being shared across all four grape cultivars. Furthermore, Pichia kluyveri was found to be prevalent among all cultivars except Petit Manseng, while H. guilliermondii was uniquely shared by Chardonnay and Petit Verdot. Different strains of the same species from different grape cultivars significantly differed in their colony morphology. In terms of aroma, Marselan wine had the highest concentrations of ethyl acetate and ethyl lactate, while Petit Manseng wine was the richest in decyl acetate, butyl acetate, and isoamyl alcohol. This suggested that, besides the inherent differences in grape cultivars, the diversity of yeast strains played a significant role in shaping the distinct aromatic profiles of wine. These results indicated that the yeast resources in the wine producing region of Penglai, Shandong were highly diverse and abundant. This study provides theoretical and practical foundations for the selection of unique yeast strains from this wine producing region to enhance and shape the distinct style of wine from Penglai, Shandong.

Key words: wine procuring region of Penglai, Shandong; wine; spontaneous fermentation; yeast diversity; Saccharomyces cerevisiae; non-Saccharomyces