Abstract
AbstractCultural exchange of fermentation techniques has driven the spread ofSaccharomyces cerevisiaeacross the globe, establishing wild populations in many countries. Despite this, most modern commercial fermentations are inoculated using monocultures, rather than relying on natural populations, potentially impacting wild population diversity. Here we investigate the genomic landscape of 411 wildS. cerevisiaeisolated from spontaneous grape fermentations in Australia across multiple locations, years, and grape cultivars. Spontaneous fermentations contained highly recombined mosaic strains that commonly exhibited aneuploidy of chromosomes 1, 3, 6 and 9. Assigning wild genomic windows to putative ancestral origin revealed that few closely related commercial lineages have come to dominate the genetic landscape, contributing most of the genetic variation. Fine-scale phylogenetic analysis of loci not observed in strains of commercial wine origin identified widespread admixture with the Beer2 clade along with three independent admixture events from potentially endemic Oceanic lineages that last shared an ancestor with modern East AsianS. cerevisiaepopulations. Our results illustrate how commercial use of microbes can affect local microorganism genetic diversity and demonstrates the presence of non-domesticated, non-European derived lineages ofS. cerevisiaein Australian ecological niches that are actively admixing.
Publisher
Cold Spring Harbor Laboratory