Diversity and Dynamics of Yeasts During Vidal Blanc Icewine Fermentation: A Strategy of the Combination of Culture-Dependent and High-Throughput Sequencing Approaches

Abstract

In this study, attention has been focused on the ecology of yeasts during the spontaneous and inoculated fermentation processes of Vidal blanc icewine in northeast China, which is very important for screening autochthonous yeast strains, understanding the roles of these strains, and managing fermentation. The strategies were to conduct spontaneous and inoculated laboratory-scale fermentation processes simultaneously and to analyze the samples taken at different fermentation stages by culture-dependent and -independent methods. Three hundred and thirty-eight yeast strains were isolated and twelve genera were identified by sequencing. During the spontaneous fermentation process, non- Saccharomyces yeasts were predominant in the initial and middle stages, whereas Saccharomyces dominated in the later stages; Candida was preponderant in the whole process, and its abundance in the final stages was only lower than Saccharomyces. The inoculated fermentation was characterized by a predominance of Saccharomyces throughout the fermentation process; non- Saccharomyces yeasts were observed in the early stage. The internal transcribed spacer (ITS) 2 region gene was firstly used to analyze the yeast diversity in the samples during the icewine fermentation processes by high-throughput sequencing (HTS), and a more complex mycobiota was revealed. Moreover, the dynamics of other major fungi (mainly Davidiella and Alternaria ) during icewine fermentation processes were also revealed, which have never been reported in icewine before.

Effects of Simultaneous Co-Fermentation of Five Indigenous Non-Saccharomyces Strains with S. cerevisiae on Vidal Icewine Aroma Quality

“…Canonico et al [ 61 ] reported that the concentration of acetic acid in beer produced by mixed fermentation was significantly higher than that produced by pure culture with T. delbrueckii . However, Li et al [ 1 ] reported that C. zemplinina mixed-fermented with S. cerevisiae reduced the ethanol and acetic acid concentrations. In our study, only the acetic acid concentration of wines mixed-fermented with F33 and S. crataegensis YC30 and R. lusitaniae QTX15 increased, whereas it was reduced in other wine samples.…”

“…Icewine is a kind of sweet wine that is made by delaying the harvest, allowing the grapes to hang on the vine for a certain period of time, followed by freezing, harvesting, and pressing the grapes at low temperature, and brewing [ 1 ]. Delaying harvesting increases the concentrations of sugars, acids, aroma compounds, and some non-volatile substances in the grapes, intensifying the flavor characteristics.…”

Fungal Diversity Analysis of Grape Musts from Central Valley-Chile and Characterization of Potential New Starter Cultures

“…In fact, high alcohol contents were measured in both EF samples, with values of 11.4 ± 0.2 and 13.6 ± 1.3% v/v for years 2016 and 2017, respectively. In contrast, during the spontaneous fermentation process, Saccharomyces dominates later stages of fermentation, whereas non-conventional yeasts can be predominant in the initial and middle stages [ 49 ]. These results support the relevance of the fermentation process over yeast selection, and therefore over the structure of the microbial community [ 14 ].…”

Craft Beers Fermented by Potential Probiotic Yeast or Lacticaseibacilli Strains Promote Antidepressant-Like Behavior in Swiss Webster Mice

“…paracasei DTA 81 was enumerated on MRS agar supplemented with 135 ppm of natamycin (Merck, Darmstadt, Germany) to prevent the S. cerevisiae growth [7]. S. boulardii 17 was enumerated on the selective Wallerstein Laboratory (WL) agar medium (Oxoid, Basingstoke, UK) [13]. The drop-plate technique was applied for both lacticaseibacilli and yeast enumeration.…”