Transformation of Microbial Negative Correlations into Positive Correlations by Saccharomyces cerevisiae Inoculation during Pomegranate Wine Fermentation

Abstract

The application of starter is a common practice to accelerate and steer pomegranate wine fermentation process. However, the use of starter needs to better understand the effect of the interaction between starter and native microorganisms during alcoholic fermentation. In this study, high-throughput sequencing combined with metabolite analysis were applied to analyze the effect of commercial Saccharomyces cerevisiae inoculation on the native fungal community interaction and metabolism during pomegranate wine fermentation. Results showed there were diverse native fungi in pomegranate juice, including Hanseniaspora uvarum, H. valbyensis, S. cerevisiae, Pichia terricola and Candida diversa. Based on ecological network analysis, we found S. cerevisiae inoculation transformed the negative correlations into positive correlations among the native fungal communities, and decreased the Granger causalities between native yeasts and volatile organic compounds. This might lead to the decreased contents of isobutanol, isoamylol, octanoic acid, decanoic acid, ethyl laurate, ethyl acetate, ethyl hexadecanoate, phenethyl acetate and 2-phenylethanol during fermentation. This study combined correlation and causality analysis to gain a more integrated understanding of microbial interaction and the fermentation process. It provided a new strategy to predict certain behaviors between inoculated and selected microorganisms and those coming directly from the fruit. IMPORTANCE Microbial interactions play an important role in flavor metabolism during traditional foods and beverages fermentation. However, we understand little about how selected starters influence the interactions among native microorganisms. In this study, we found S. cerevisiae inoculation changed the interactions and the metabolisms of the native fungal communities during pomegranate wine fermentation. This study suggest that the starters inoculation should take into account not only the positive features of starters, but also to characterize the microbial interactions established among the starters and native communities. It may be helpful to select the appropriate starter cultures for winemakers to design different styles of wine.

Dynamics of the Fermentation Process and Chemical Profiling of Pomegranate (Punica granatum L.) Wines Obtained by Different Cultivar×Yeast Combinations

“…Isoamyl alcohol and 2-phenylethanol were the alcohols found in highest amounts, while the most abundant esters were isoamyl acetate and phenylethyl-acetate (among acetates), ethyl hexanoate, and octanoate and decanoate (among ethyl esters). Similar volatile profiles were reported in the literature [27,36,41,42]. Several significant differences were however observed in the levels of volatile compounds, due to both Cultivar and Yeast variables.…”

Biocontrol of Geosmin Production by Inoculation of Native Microbiota during the Daqu-Making Process

“…S. cerevisiae is one of the most important species in fermented foods and contributes to the production of alcohols and esters [47]. In winemaking, S. cerevisiae is widely used as a starter culture [48]. Moreover, inoculation with S. cerevisiae has been recommended to enhance flavor complexity and microbial community stability.…”

“…Moreover, inoculation with S. cerevisiae has been recommended to enhance flavor complexity and microbial community stability. For example, pomegranate wine fermentation with S. cerevisiae inoculation transformed the negative correlations into positive correlations among the fungal communities [48]. Inoculated S. cerevisiae can suppress wild microflora, determining the starter's ability to dominate the process [49].…”

Microbial diversity analysis of vineyard son the eastern foothills of the Helan Mountain region using high-throughput sequencing

“…Kioroglou et al found that oak barrel aging had no significant effect on microbial diversity during the wine aging process, but did alter the population structure and composition of fungi and bacteria (Ma et al, 2018). Using highthroughput sequencing technology, Wang et al (2020b) found that inoculation with starter cultures altered the interactions and metabolism of primitive fungal communities during pomegranate wine fermentation. Therefore, not only the positive characteristics of the starter culture, but also the interaction between the starter culture and the original flora should be considered in starter culture inoculation (Kioroglou et al, 2020).…”

“…Therefore, not only the positive characteristics of the starter culture, but also the interaction between the starter culture and the original flora should be considered in starter culture inoculation (Kioroglou et al, 2020). Wang et al (2020b) analyzed the traditional fungal resources…”