Saccharomyces eubayanus
From Wikipedia, the free encyclopedia
| Saccharomyces eubayanus | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Saccharomycetes |
| Order: | Saccharomycetales |
| Family: | Saccharomycetaceae |
| Genus: | Saccharomyces |
| Species: | S. eubayanus |
| Binomial name | |
| Saccharomyces eubayanus J.P. Samp., Libkind, Hittinger, P. Gonç., E. Valério, C. Gonç., Dover & M. Johnst. | |
Saccharomyces eubayanus, a cryotolerant (cold tolerant) type of yeast, is most likely the parent of the lager brewing yeast, Saccharomyces pastorianus.[1][2][3] It is also a parent of Saccharomyces bayanus, a wine and cider yeast.[4]
Lager is a type of beer created from malted barley and fermented at low temperatures, originally in Bavaria. S. eubayanus was first discovered in Patagonia[4] and is capable of fermenting glucose, along with the disaccharide maltose at reduced temperatures. Although originally considered a possible case of Columbian exchange,[5] Tibetan (Himalayan) strains of S. eubayanus proved more similar to S. pastorianus than the Patagonian strains at 99.82%.[6][7]
With the emergence of lager beer in the 14th century, S. eubayanus was considered to be the progenitor of S. pastorianus along with S. cerevisiae.[1] Since 1985 the non-cerevisiae ancestor has been contentiously debated between S. eubayanus, and S. bayanus which "is not found outside the brewing environment".[1][dubious – discuss] Upon the 2011 discovery of S. eubayanus in Argentina and consequential genome analysis, S. eubayanus was found to be 99% genetically identical to S. pastorianus and S. bayanus was dismissed as an ancestor.[1]
First described in 2011, S. eubayanus was discovered in North Patagonia, ecologically associated with Nothofagus spp. (Southern Beech) forests and the parasitic biotrophic fungi Cyttaria spp.[1][2] With discoveries in other parts of the world shortly after in east Asia, the South American origins of S. eubayanus have been challenged by genomic and phylogenetic evidence that suggests a Tibetan origin.[6] The proponents of this theory argue that it "corresponds better with geography and world trade history" given the Eurasian land bridge.[6] Since then, genomic analyses from South America strains have shown reduced genetic diversity suggesting a biogeographical radiation point from Patagonia.[1]
In 2022, a researcher team from the University College Dublin isolated Saccharomyces eubayanus from soil samples in Ireland.[8] Further isolations from different locations in Europe can be expected.
Phylogenetically, S. eubayanus is basal in the Saccharomyces genus, and well-adjusted to the cooler environment of Nothofagus forests, Saccharomyces species with thermo-tolerance are suggested to be derived traits.[1]