Multiple genetic origins of Saccharomyces cerevisiae in bakery

Abstract

International audienceSaccharomyces cerevisiae is an ubiquitous yeast species found in natural and domesticated habitats. It has been domesticated to make a wide diversity of fermented products like wine, sake, beer, cocoa and bread. While bread is of cultural and historical importance, the domestication of S. cerevisiae in bread making is poorly known. Bread can be made either by adding commercial S. cerevisiae strains or by propagating a natural sourdough, which is a mixed of naturally fermented flour, water containing yeast and bacteria. Here we analysed the genetic diversity of 229 S. cerevisiae strains of commercial and sourdough origins to get more insight into bakery yeast domestication.The origin of bakery strains is polyphyletic. No geographical structuration were found neither for commercial nor for natural sourdough strains. Selection for commercial strains has maintained autotetraploid. Commercial strains are mostly related to strains of the Mixed origin clade on the 1002 genomes tree, which also includes beer strains. Sourdough strains are mosaic and are genetically related to strains from highly diverse environments like human, wine, sake, fruits, tree, soil... Saccharomyces cerevisiae is an ubiquitous yeast species found in natural and domesticated habitats. It has been domesticated to make a wide diversity of fermented products like wine, sake, beer, cocoa and bread. While bread is of cultural and historical importance, the domestication of S. cerevisiae in bread making is poorly known. Bread can be made either by adding commercial S. cerevisiae strains or by propagating a natural sourdough, which is a mixed of naturally fermented flour, water containing yeast and bacteria. Here we analysed the genetic diversity of 229 S. cerevisiae strains of commercial and sourdough origins to get more insight into bakery yeast domestication