Ötzi, the snowman who is more than 5,300 years old, «is not a static relic», but a dynamic ecosystem that «constitutes a living archive» in which microorganisms coexist ancient glaciers and modern pollutants, according to a new study on the mummy.
Ötzi was discovered in the Italian Alps in 1991 by German tourists and is the oldest known mummy preserved in ice. Numerous studies have been carried out on his remains that have revealed everything from his possible physical appearance, to what you last ate.
New research published Microbiomefrom the group Naturefocuses on its microbiome, which ranges from the intestinal flora of a Copper Age human being to yeasts adapted to the cold, which could have accompanied the mummy for millennia and which continue to be part of a «active ecosystem» to this day.
The team of researchers, led by the Eurac Research Institute (Italy), distinguished which microorganisms were already present in the body in life and which colonized it later, both during the time it remained on the glacier and throughout the three decades of conservation.
The findings suggest that while the current method used to preserve remains slows the growth of most microbes, it could also keep some organisms alive capable of thriving under conservation conditions.
The researchers analyzed bacteria and fungi found in skin smears, tissue fragments and thawed internal water samples from the mummified remains, which they compared with soil and ice samples collected at the discovery site and preserved in 1991, to determine environmental influences.
His body has signs of life
In the internal tissue samples, genetic material from bacteria belonging to their original intestinal flora, a type of bacteria that are rarely found in the intestines of humans living in industrialized societies, so Ötzi offers, according to Eurac, «an exceptional insight into humanity’s microbial past.»
Furthermore, the presence of cold-adapted yeast species was detected, probably originating from the glacial environment, and which have persisted in the mummy to the present day.
«The iceman is not a static relic, but a dynamic biological interface» and the coexistence of ancient endogenous gut microbes and modern colonizers «highlights the possibility of microbial activity even at subzero temperatures,» the research points out.
The researchers they found DNA both highly degraded (ancient) and well preserved (modern), which reveals that these microorganisms are not mere vestiges of the past, but continue to exist under current conservation conditions, despite six degrees below zero and high humiditypossibly in a latent state.
The study also indicates that previous conservation measures may have unintentionally favored certain microorganisms, since three of the four yeasts identified have the genetic capacity to decompose phenol.
That compound was used after Ötzi’s discovery to eliminate fungal growth from the surface of the mummy that the yeasts could have used as a food source.
The microbiome of a mummy «is unique because we are dealing with microbes that are more than 5,000 years old and, at the same time, modern microbes that have been introduced since the discovery,» said the lead author of the article, Mohamed Sarhan.
These findings (says the study) «underscore that it is essential to maintain strict environmental parameters to prevent these specialized microbial communities from moving from a state of dormant persistence to becoming active microorganisms», although, so far, no indication of damage has been observed.
The conservation conditions of the mummy are currently «very stable», in the words of the director of the Archaeological Museum of South Tyrol, Elisabeth Vallazza, who oversees the conservation of the mummy, but «further research and a comprehensive conservation effort are needed to preserve it for many more generations.»
EFE Agency.
GML
