Image: Humans have a long history of fermenting food and beverages that led to domestication of the baker's yeast, Saccharomyces cerevisiae. Humans domesticated baker’s yeast as early as 7000 BCE to make bread, beer, wine and sake. However, wild varieties of the same yeast species also live on trees. These domesticated and wild yeast look different genetically, and Douda Bensasson, Associate Professor in Plant Biology, and her lab explored possible links between the two. Their work was published in the Feb 4 issue of Molecular Ecology. The researchers, including current and former graduate students Jacqueline J. Peña, Eduardo F. C. Scopel, Audrey K. Ward used over 300 genomes of S. cerevisiae from oaks and other trees from Europe, Japan, and North America. “We were expecting that these would be ancient divergences and that the forest yeast would’ve had nothing to do with humans this whole time,” said Bensasson. “But to our surprise, we found that it roughly coincided with the last ice age, which is around the time that humans were starting to grow their own food and spreading farming around the world.” While examining the yeast from different regions, Peña and Bensasson found something strange — yeast in the winemaking regions of southern Europe resembled those found in the southern U.S. And their data suggested the yeast was brought over from the U.S. in the last few hundred years. The researchers believe this may be due to the Great French Wine Blight. In the 1850s, humans accidentally introduced an insect pest to Europe, devastating vineyards in the region. To save the wine industry, workers brought vines resistant to the bug over from North America. Since they couldn’t make wine from the grapes due to the fruit’s low quality, they instead grafted European vines onto North American rootstock. In doing so, yeast living in the North American vines were passed on to their European counterparts. This is a modified excerpt from the article by Sydney Barrilleaux, published on April 28 in UGA Today. Read the full article in UGA Today and the study in Molecular Ecology.
