Dynamic Changes in Yeast Populations and Aroma Composition of ‘Beimei’ (Vitis vinifera × Vitis amurensis) during Spontaneous Fermentation

Abstract ‘Beimei’ is a hybrid cultivar of Vitis vinifera and wild Vitis amurensis with fungus- and cold-resistant characteristics that is widely grown in many regions of China. However, studies on the yeast diversity and aroma compound composition of this cultivar remain scarce. Here, indigenous yeast diversity, aroma compound composition, and their dynamic changes during the spontaneous fermentation of ‘Beimei’ were investigated and monitored using high-throughput sequencing and gas chromatography-mass spectrometry. The result indicated that non- Saccharomyces yeasts were predominant at the initial stages of ‘Beimei’ spontaneous fermentation and then sharply decreased. Cladosporium herbarum and Hanseniaspora uvarum were identified as the dominant species of filamentous fungi and yeast, respectively, at the beginning and on the first day of fermentation, whereas unclassified_f_ Saccharomycetacease was dominant throughout fermentation, starting from the third day until the end of fermentation. The main volatile aroma chemicals were esters and alcohols, which accumulated abundantly at the late stage of fermentation. Taken together, this study represents the first step in exploring untapped yeast species and aroma compounds, which is helpful for the screening of native yeasts from ‘Beimei’ and producing distinctive aroma wines.