Ancient Egyptian rulers are famously known for their elaborate preparations for the afterlife. But it appears that one of their contemporaries may have exceeded their most ardent expectations to return to life, thanks to the efforts of a team that includes Richard Bowman, a University of Iowa doctoral candidate in biology.
The remarkable Saccharomyces cerevisiae rose again in July 2019, not where pharaohs were interred at Thebes, Egypt, but in Pasadena, California under the hands of Bowman’s co-conspirator and Xbox creator Seamus Blackley. Using Bowman’s scientific expertise, Blackley was able to extract a sample from an ancient loaf of bread that belongs in the ancient Egypt collection of the Museum of Fine Arts, Boston. With the extracted yeast and the same grains used by ancient Egyptians Blackley was able to re-create a loaf of ancient Egyptian bread.
Saccharomyces cerevisiae might be mistaken for the name of some fallen pharaoh, but it is actually a species of very common, but tremendously important yeast. The genus name Saccharomyces identifies it as a fungus that feeds on sugars, and cerevisiae hints at its relationship to beer. Without the services of S. cerevisiae you would not be able to celebrate a special occasion with a glass of wine nor enjoy the aroma of a freshly baked loaf of bread.
So what makes this story so special if S. cerevisiae is so common? This yeast did not need the protection of a massive pyramid nor a copy of “The Book of the Dead” to help guide it back to the land of the living. Assuming confirmation by genome sequencing, this yeast will have survived over 4,000 years buried in an Egyptian temple foundation deposit, due to its ability to arrest its metabolism and enter a quiescent (one might be tempted to say near deathlike) state called dormancy, which it does through sporulation when starved of nutrients.
Blackley and Bowman will continue collecting yeast samples from additional museums with artifacts that represent the Old, Middle, and New Kingdom periods of Egyptian history, a period that spans over a thousand years. After analyzing the yeast genomes from those samples, they hope to characterize the genetic changes that S. cerevisiae has undergone during that time, and publish their findings in a scientific journal. We eagerly await their report.
Check back for the next installment of this three-part series Rising Together: Yeast and Humankind. Thank you to Kai Weatherman for whipping up this stirring series!