Wild Yeast for the Future: Exploring the Use of Wild Strains for Wine and Beer Fermentation

Abstract

The continuous usage of single Saccharomyces cerevisiae strains as starter cultures in fermentation led to the domestication and propagation of highly specialized strains in fermentation, resulting in the standardization of wines and beers. In this way, hundreds of commercial strains have been developed to satisfy producers' and consumers' demands, including beverages with high/low ethanol content, nutrient deprivation tolerance, diverse aromatic profiles, and fast fermentations. However, studies in the last 20 years have demonstrated that the genetic and phenotypic diversity in commercial S. cerevisiae strains is low. This lack of diversity limits alternative wines and beers, stressing the need to explore new genetic resources to differentiate each fermentation product. In this sense, wild strains harbor a higher than thought genetic and phenotypic diversity, representing a feasible option to generate new fermentative beverages. Numerous recent studies have identified alleles in wild strains that could favor phenotypes of interest, such as nitrogen consumption, tolerance to cold or high temperatures, and the production of metabolites, such as glycerol and aroma compounds. Here, we review the recent literature on the use of commercial and wild S. cerevisiae strains in wine and beer fermentation, providing molecular evidence of the advantages of using wild strains for the generation of improved genetic stocks for the industry according to the product style.

Unique Brewing-Relevant Properties of a Strain of Saccharomyces jurei Isolated From Ash (Fraxinus excelsior)

“… Peris et al (2018) provides an extensive overview of the various occurrences of these hybrids. Molinet and Cubillos (2020) also give an overview of the use and generation of Saccharomyces interspecific hybrids and the generation of intraspecific hybrids of commercial S. cerevisiae and wild S. cerevisiae strains.…”

Mixed culture metagenomics of the microbes making sour beer

“…However, there is still a little-known world of unconventional yeasts to be discovered and characterized, which comprises less common genera such as Issatchenkia and Wickerhamomyces . The fungal microbiomes presented a lower variability in the number of species when compared to bacteria, which may be related to avidity in glucose consumption by commercial strains (reducing the concentration of carbohydrates with easy assimilation in the medium) and the competition among yeasts, which can present killer characteristics, producing secondary metabolites that aim to stop the multiplication of cross-feed competitors [14,15]. Even so, 12 different yeast genera were detected participating in these fermentations.…”

“…The identification of the yeasts in the metagenomes of our samples revealed only one species in the Saccharomyces genus, S. cerevisiae , which together with S. pasteurianus are the brewer’s yeasts most used for beer fermentation and are widely commercially available through propagation laboratories [36]. Wild strains of S. cerevisiae can offer interesting characteristics, such as extracellular production of different secondary metabolites (related to the production of new aromas) and tolerance to different stress conditions ( e.g ., salinity, temperature, and high levels of ethanol) [15]. These strains have mainly been isolated and characterized from spontaneous fermentations of traditional fermented beverages, such as Kveik strains, isolated from traditional beers named Norwegian Kveik Beer [37].…”

“…Wild strains of S. cerevisiae can offer interesting characteristics, such as extracellular production of different secondary metabolites (related to the production of new aromas) and tolerance to different stress conditions ( e . g ., salinity, temperature, and high levels of ethanol) [19]. These strains have mainly been isolated and characterized from spontaneous fermentations of traditional fermented beverages, such as Kveik strains, isolated from Norwegian Kveik Beer [41].…”

Role of Yeasts in the Brewing Process: Tradition and Innovation

“…The production and quantity of these compounds depend on the yeast strains involved in the fermentation process and, therefore, their choice is of fundamental importance [3,[30][31][32][33][34][35][36][37][38][39]. In addition to the traditional S. pastorianus and S. bayanus natural hybrids strains [4,40] that have been used extensively by the brewing industry [23], the recent discovery of S. eubayanus [41] has allowed the creation of brewing yeast hybrids generated by de novo hybridization [42][43][44][45][46][47][48].…”