Abstract: This study aimed to understand the potential application of indigenous Pichia kluyveri in winemaking and its impact on wine aroma. Mixed starter cultures of P. kluyveri HS-2-1 and Saccharomyces cerevisiae NX11424 at ratios of 1:1, 10:1 and 20:1 were separately used to ferment Cabernet Sauvignon wine. Results showed that HS-2-1 propagated well in the mixed culture fermentation. Compared with pure fermentation by NX11424, wines produced by mixed fermentation contained less volatile acid as well as significantly higher levels of esters and higher alcohols with the highest increase being 24.19% and 21.34% at 20:1 ratio, respectively. Additionally, the concentrations of isopentanol, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl 9-decenoate and ethyl lactate increased with increased proportion of HS-2-1 in the mixed inoculum, thus enhancing the fruity and floral aroma of the wine. To our knowledge, this study is the first to indicate that strain HS-2-1 exhibits good enological characteristics, and further highlight its potential application in wine-making by co-fermentation with S. cerevisiae NX11424 at a ratio of 20:1.

Key words: Pichia kluyveri, mixed fermentation, aroma enhancement fermentation, red wine