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Title: Complex ancestries of lager-brewing hybrids were shaped by standing variation in the wild yeast Saccharomyces eubayanus

Lager-style beers constitute the vast majority of the beer market, and yet, the genetic origin of the yeast strains that brew them has been shrouded in mystery and controversy. Unlike alestyle beers, which are generally brewed with Saccharomyces cerevisiae, lagers are brewed at colder temperatures with allopolyploid hybrids of Saccharomyces eubayanus x S. cerevisiae. Since the discovery of S. eubayanus in 2011, additional strains have been isolated from South America, North America, Australasia, and Asia, but only interspecies hybrids have been isolated in Europe. Here, using genome sequence data, we examine the relationships of these wild S. eubayanus strains to each other and to domesticated lager strains. Our results support the existence of a relatively low-diversity (π = 0.00197) lineage of S. eubayanus whose distribution stretches across the Holarctic ecozone and includes wild isolates from Tibet, new wild isolates from North America, and the S. eubayanus parents of lager yeasts. This Holarctic lineage is closely related to a population with higher diversity (π = 0.00275) that has been found primarily in South America but includes some widely distributed isolates. A second diverse South American population (π = 0.00354) and two early-diverging Asian subspecies are more distantly related. We further showmore » that no single wild strain from the Holarctic lineage is the sole closest relative of lager yeasts. Instead, different parts of the genome portray different phylogenetic signals and ancestry, likely due to outcrossing and incomplete lineage sorting. Indeed, standing genetic variation within this wild Holarctic lineage of S. eubayanus is responsible for genetic variation still segregating among modern lager-brewing hybrids. Furthermore, we conclude that the relationships among wild strains of S. eubayanus and their domesticated hybrids reflect complex biogeographical and genetic processes.« less
ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [1] ;  [4]
  1. Univ. of Wisconsin, Madison, WI (United States)
  2. Univ. Laval, Quebec City, QC (Canada)
  3. Centro Regional Univ. Bariloche, Rio Negro (Argentina)
  4. Washington Univ. School of Medicine, St. Louis, MO (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
PLoS Genetics
Additional Journal Information:
Journal Volume: 12; Journal Issue: 7; Journal ID: ISSN 1553-7404
Public Library of Science
Research Org:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org:
Country of Publication:
United States
OSTI Identifier: