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Headline: Scientists 'create sourdough bread' from yeast found in Ötzi the Iceman's 5,000-year-old gut
Caption: **VIDEO AVAILABLE: CONTACT INFO@COVERMG.COM TO RECEIVE** BY MARK WORGAN Scientists have used yeast from the gut of Ötzi the Iceman to make sourdough bread. Researchers have uncovered new insights into the complex microbial ecosystem surrounding Ötzi the Iceman, revealing that some cold-adapted microorganisms from the Alpine glacier where he was found may have remained associated with the mummy for thousands of years. Using a range of samples and analytical techniques, scientists were able to distinguish between microorganisms that were present during Ötzi’s lifetime and those that colonised his remains after death, both during his time in the glacier and throughout more than three decades of modern preservation. “We see continuity here,” explains Frank Maixner, director of the Institute for Mummy Studies at Eurac Research: “These yeasts have accompanied Ötzi on his long journey through the millennia.” According to Dr Maixner, the findings demonstrate that the mummy is “not a static relic, but a dynamic biological system”. As part of the project, scientists reproduced one of the gut yeast strains in a refrigerator and attempted to use it in baking. After three months of trying they were able to produce sourdough bread. While the bread-making experiment provided a lighter moment in the research, the scientists believe the microorganisms may have more significant applications. Cold-adapted microorganisms could, for example, be used in energy-efficient industrial processes such as low-temperature fermentation. Their next plan however, is to use the yeast to brew an Ötzi the Iceman beer. The team identified genetic material from bacteria belonging to Ötzi’s original gut microbiome in samples of internal tissue. They also made what they described as a surprising discovery: cold-adapted yeast species, believed to originate from the glacial environment, are still present on the mummy today. The research involved an extensive investigation of the mummy and its surroundings. Scientists analysed ice from the surface of the body and meltwater collected from within the mummy, while also taking numerous swab samples. They supplemented this with data from previous studies of intestinal tissue and stomach contents. “A mummy’s microbiome is unique because we are dealing with microbes that are over 5,000 years old and, at the same time, with modern microbes that have been introduced since the discovery,” says microbiologist and lead author Mohamed S. Sarhan. A soil sample collected from the site where Ötzi was discovered in 1991 and frozen during his recovery was also examined to help trace environmental influences. Researchers confirmed the presence of genetic material from Ötzi’s original gut microbiome in both the intestinal tract and stomach contents. First described in a 2019 study conducted with Eurac Research, this ancient microbiome closely resembles the limited number of known gut microbial communities from early human populations. Such bacteria are rarely found in people living in modern industrialised societies, offering what scientists say is a rare glimpse into humanity’s microbial past. The newly identified yeasts were isolated from skin samples, meltwater from inside the mummy and stomach-content samples. These highly specialised organisms are adapted to survive in extremely cold conditions. Genetic analysis showed similarities with strains found in some of the coldest places on Earth, including Antarctica. According to the researchers, this indicates the yeasts likely originated in the glacial environment and may have remained associated with the mummy for millennia. The scientists detected both heavily degraded ancient DNA and well-preserved modern DNA. They say this suggests the microorganisms are not simply remnants of the distant past but continue to survive under present-day conservation conditions, which maintain the mummy at minus six degrees Celsius and high humidity, possibly in a dormant state. The study also indicates that some earlier conservation measures may have inadvertently encouraged the growth of certain microorganisms. Three of the four yeast species identified possess the genetic ability to break down phenol, a substance applied after Ötzi’s recovery to remove fungal growth from the mummy’s surface. Researchers suggest the yeasts may have used the compound as a source of nutrients. “The mummy’s conservation conditions are very stable today,” comments Elisabeth Vallazza, director of the South Tyrol Museum of Archaeology, which oversees the mummy’s preservation, “close microbiological monitoring ensures that the mummy suffers no damage. But further research and full conservation efforts are certainly needed to preserve it for many more generations.” Conservation expert and co-author Marco Samadelli emphasizes: "The conditions under which glacial mummies are preserved are not yet fully understood. This study expands our knowledge in this area.” The finding were published in the journal Microbiome.
Keywords: otzi,feature,photo,video,iceman,science
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