ÖTZTAL ALPS — A new study published June 3 in Microbiome identified cold-adapted yeasts on Ötzi the Iceman’s remains that may have colonized him during his glacial preservation. Researchers grew living colonies from four species of yeast found in Ötzi’s body, suggesting the 5,300-year-old mummy is not a static relic but a dynamic biological interface.
Scientists collected samples by thawing Ötzi’s remains to 4° Celsius for five hours and gathering runoff, in addition to taking swabs from his skin and internal tissues. They also analyzed soil from the glacier where he was discovered in 1991, the air in his museum storage chamber, and the water used to humidify that space. Comparison of skin samples collected in 2010 and 2019 showed that the cold-loving yeast Glaciozyma became the dominant strain over that nine-year period.
Frank Maixner, director of the Eurac Research Institute for Mummy Studies, said, “These yeasts have accompanied Ötzi on his long journey through the millennia.” He stated that Ötzi is “not a static relic, but a dynamic biological interface.” Albert Zink, an anthropologist formerly with the Eurac research center and now at Ludwig Maximilian University of Munich, said, “We also found ancient DNA from these species, which proves that they persisted in Ötzi and accompanied him over thousands of years while he was preserved in the ice.”
The study notes there could be a danger of decomposition if the yeasts are not kept frozen. Ötzi’s remains are stored in a specialized facility in Italy at –6° Celsius to simulate glacial conditions and prevent degradation. Researchers found evidence of ancient DNA damage in the yeasts, suggesting they either remained dormant for millennia or are descendants of the original colonizers.
Patrick Hunt of Stanford University, an Alpine archaeologist not involved in the study, said the conclusion that Ötzi is a “dynamic biological interface” is “right on the mark.” Hunt stated that the team’s “analytical findings on ongoing microbial contamination are vital to whatever interventions are needed.” The study acknowledges it is currently unclear whether modern microbes introduced during conservation or the ancient yeasts pose a risk to his continued preservation.