Bachinskaya, A.A., 1914
Saccharomyces paradoxus is a wild yeast and the closest known species to the baker's yeast Saccharomyces cerevisiae. It is used in population genomics and phylogenetic studies to compare its wild characteristics to laboratory yeasts.
Saccharomyces paradoxus is mostly isolated from deciduous trees (oak, maple, birch), and in some rare occasions on insects and fruits. It is often found in sympatry with other Saccharomyces species. Like Saccharomyces cerevisiae, it has a worldwide distribution and it is mesophilic, which limits its natural distribution to low latitudes. However, Saccharomyces paradoxus typically grows at lower temperatures than Saccharomyces cerevisiae, resulting in a slight shift in its distribution toward cooler regions, like British islands and Eastern Canada.
Unlike most other Saccharomyces species, there is no evidence that Saccharomyces paradoxus has been domesticated by humans. Accordingly, its biogeography is mostly marked by natural processes like limited migration, glacial refugia  and adaptation to climate. At least four genetically and phenotypically distinct populations of Saccharomyces paradoxus have been identified, corresponding to main geographical divisions: Europe (including West Siberia), Far East Asia (Japan, Eastern Siberia), North America (North American East and West coasts, Great Lakes region) and North-East America (Gaspé Peninsula, Saint Lawrence Valley and Appalaches), respectively. Representative strains of these populations exhibit partial post-zygotic isolation. A fifth population is represented by a singleton isolate from Hawaii. Some strains from the European population are found in North America and New Zealand and likely result from recent colonization events. Two isolates from South America, described as Saccharomyces cariocanus, are genetically indistinguishable but exhibit post-zygotic isolation when crossed to strains from the American population, due to chromosomal translocations.
Saccharomyces paradoxus is naturally homothallic, and is mostly found as diploid in the environment. Reproduction is mostly clonal and 99% of sexual reproduction occurs between spores from the same ascus. This purges recessive deleterious mutations that accumulated during clonal expansion, in a process known as "genome renewal". Post-zygotic isolation between strains of Saccharomyces paradoxus is commonly observed and could be either due to genetic divergence between populations or to chromosomal changes within populations.
- Dunham, MJ; Louis, ED (2011). "Yeast evolution and ecology meet genomics". EMBO Reports. 12 (1): 8–10. doi:10.1038/embor.2010.204. PMC 3024138.
- Charron, G; Leducq, J-B; Bertin, C (2014). "Exploring the northern limit of the distribution of Saccharomyces cerevisiae and Saccharomyces paradoxus in North America". FEMS Yeast Research. 14: 281–8. doi:10.1111/1567-1364.12100.
- Hyma, KE; Jay, JC (2013). "Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards". Molecular Ecology. 22: 2917–30. doi:10.1111/mec.12155. PMC 3620907. PMID 23286354.
- Maganti, H; Bartfai, D; Xu, J (2012). "Ecological structuring of yeasts associated with trees around Hamilton, Ontario, Canada". FEMS Yeast Research. 12: 9–19. doi:10.1111/j.1567-1364.2011.00756.x.
- Sniegowski, PD; Dombrowski, PG; Fingerman, E (2002). "Saccharomyces cerevisiae and Saccharomyces paradoxus coexist in a natural woodland site in North America and display different levels of reproductive isolation from European conspecifics". FEMS Yeast Research. 1: 299–306. doi:10.1111/j.1567-1364.2002.tb00048.x.
- Naumov, GI; Naumova, ES; Sniegowski, PD (1998). "Saccharomyces paradoxus and Saccharomyces cerevisiae are associated with exudates of North American oaks". Canadian Journal of Microbiology. 44 (11): 1045–50. doi:10.1139/w98-104. PMID 10029999.
- Sampaio, JP; Goncalves, P (2008). "Natural populations of Saccharomyces kudriavzevii in Portugal are associated with oak bark and are sympatric with S. cerevisiae and S. paradoxus" (PDF). Applied and Environmental Microbiology. 74: 2144–52. doi:10.1128/AEM.02396-07. PMC 2292605. PMID 18281431.
- Sweeney, JY; Kuehne, HA; Sniegowski, PD (2004). "Sympatric natural Saccharomyces cerevisiae and S. paradoxus populations have different thermal growth profiles". FEMS Yeast Research. 4 (4–5): 521–5. doi:10.1016/s1567-1356(03)00171-5. PMID 14734033.
- Johnson, LJ; Koufopanou, V; Goddard, MR (2004). "Population genetics of the wild yeast Saccharomyces paradoxus". Genetics. 166 (1): 43–52. doi:10.1534/genetics.166.1.43. PMC 1470673. PMID 15020405.
- Leducq, J-B; Charron, G; Samani, P (2014). "Local climatic adaptation in a widespread microorganism". Proceedings of the Royal Society B: Biological Sciences. 281: 20132472. doi:10.1098/rspb.2013.2472. PMC 3896012. PMID 24403328.
- Liti, G; Carter, DM; Moses, AM (2009). "Population genomics of domestic and wild yeasts". Nature. 458: 337–41. doi:10.1038/nature07743. PMC 2659681. PMID 19212322.
- Charron, G; Leducq, J-B; Landry, CR (2014). "Chromosomal variation segregates within incipient species and correlates with reproductive isolation". Molecular Ecology. 23: 4362–4372. doi:10.1111/mec.12864. PMID 25039979.
- Liti, G; Barton, DB; Louis, EJ (2006). "Sequence diversity, reproductive isolation and species concepts in Saccharomyces". Genetics. 174 (2): 839–850. doi:10.1534/genetics.106.062166. PMC 1602076. PMID 16951060.
- Kuehne, HA; Murphy, HA; Francis, CA (2007). "Allopatric divergence, secondary contact, and genetic isolation in wild yeast populations". Current Biology. 17 (5): 407–11. doi:10.1016/j.cub.2006.12.047. PMID 17306538.
- Zhang, HA; Skelton, A; Gardner, RC (2010). "Saccharomyces paradoxus and Saccharomyces cerevisiae reside on oak trees in New Zealand: evidence for migration from Europe and interspecies hybrids". FEMS Yeast Research. 10: 941–7. doi:10.1111/j.1567-1364.2010.00681.x.
- Naumov, GI; James, SA; Naumova, ES (2000). "Three new species in the Saccharomyces sensu stricto complex: Saccharomyces cariocanus, Saccharomyces kudriavzevii and Saccharomyces mikatae". International Journal of Systematic and Evolutionary Microbiology. 50: 1931–42. doi:10.1099/00207713-50-5-1931. PMID 11034507.
- Tsai, IJ; Bensasson, D; Burt, A (2008). "Population genomics of the wild yeast Saccharomyces paradoxus: Quantifying the life cycle". Proceedings of the National Academy of Sciences of the United States of America. 105: 4957–62. doi:10.1073/pnas.0707314105. PMC 2290798. PMID 18344325.
- Mortimer, Robert K.; Romano, Patrizia; Suzzi, Giovanna; Polsinelli, Mario (December 1994). "Genome renewal: A new phenomenon revealed from a genetic study of 43 strains ofSaccharomyces cerevisiae derived from natural fermentation of grape musts". Yeast. 10 (12): 1543–1552. doi:10.1002/yea.320101203. PMID 7725789.
- Masel, Joanna; Lyttle, David N. (December 2011). "The consequences of rare sexual reproduction by means of selfing in an otherwise clonally reproducing species". Theoretical Population Biology. 80 (4): 317–322. doi:10.1016/j.tpb.2011.08.004. PMC 3218209. PMID 21888925.