Better explicating the strengths and shortcomings of these models will help refine projections and improve transparency in the years ahead.
Image credit: Witsawat.S.
Edited by John Doebley, University of Wisconsin, Madison, WI, and approved July 20, 2011 (received for review April 5, 2011)
Abstract
Domestication of plants and animals promoted humanity's transition from nomadic to sedentary lifestyles, demographic expansion, and the emergence of civilizations. In contrast to the well-documented successes of crop and livestock breeding, processes of microbe domestication remain obscure, despite the importance of microbes to the production of food, beverages, and biofuels. Lager-beer, first brewed in the 15th century, employs an allotetraploid hybrid yeast, Saccharomyces pastorianus (syn. Saccharomyces carlsbergensis), a domesticated species created by the fusion of a Saccharomyces cerevisiae ale-yeast with an unknown cryotolerant Saccharomyces species. We report the isolation of that species and designate it Saccharomyces eubayanus sp. nov. because of its resemblance to Saccharomyces bayanus (a complex hybrid of S. eubayanus, Saccharomyces uvarum, and S. cerevisiae found only in the brewing environment). Individuals from populations of S. eubayanus and its sister species, S. uvarum, exist in apparent sympatry in Nothofagus (Southern beech) forests in Patagonia, but are isolated genetically through intrinsic postzygotic barriers, and ecologically through host-preference. The draft genome sequence of S. eubayanus is 99.5% identical to the non-S. cerevisiae portion of the S. pastorianus genome sequence and suggests specific changes in sugar and sulfite metabolism that were crucial for domestication in the lager-brewing environment. This study shows that combining microbial ecology with comparative genomics facilitates the discovery and preservation of wild genetic stocks of domesticated microbes to trace their history, identify genetic changes, and suggest paths to further industrial improvement.
Footnotes
↵1D.L. and C.T.H. contributed equally to this work.
↵2Present address: Laboratory of Genetics, University of Wisconsin, Madison, WI 53706.
- ↵3To whom correspondence should be addressed. E-mail: jss{at}fct.unl.pt.
Author contributions: D.L., C.T.H., M.J., P.G., and J.P.S. designed research; D.L., C.T.H., E.V., C.G., and J.D. performed research; D.L. and C.T.H. contributed new reagents/analytic tools; D.L., C.T.H., P.G., and J.P.S. analyzed data; and C.T.H., P.G., and J.P.S. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: Genome data have been deposited in the National Center for Biotechnology Information's Sequence Read Archive (www.ncbi.nlm.nih.gov/sra) (sequence nos. SRP006155 of SRA030851); individual genes have been deposited in GenBank (accession nos. JF786614–JF786710).
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1105430108/-/DCSupplemental.
Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast
Sign up for Article Alerts
Jump to section
You May Also be Interested in
Did the Caribbean sweep into the western Amazon millions of years ago, shaping the region’s rich biodiversity?
Image credit: Tacio Cordeiro Bicudo (University of São Paulo, São Paulo, Brazil), Victor Sacek (University of São Paulo, São Paulo, Brazil), and Lucy Reading-Ikkanda (artist).
Settlements 4,200 years ago may have suffered from overpopulation before drought and lower temperatures ultimately made them unsustainable.
Image credit: Andrea Ricci.
Mara Reed and Michael Manga explore why Yellowstone's Steamboat Geyser resumed erupting in 2018.
Some songbird parents might improve their own fitness by manipulating their offspring into leaving the nest early, at the cost of fledgling survival, a study finds.
Image credit: Gil Eckrich (photographer).