ROME, June 3 (Xinhua) -- Some cold-adapted microorganisms associated with Otzi the Iceman, a 5,300-year-old mummy, may remain biologically active under current preservation conditions, according to a study published recently in the journal Microbiome by researchers from Italy's Eurac Research.
The findings published on Tuesday could help improve conservation efforts aimed at preventing the mummy from deteriorating.
The researchers stressed that they have found no evidence of microbial damage to the remains, but recommended proactive genomic surveillance of microbial communities to prevent dormant microorganisms from becoming active.
The research team analyzed bacterial communities detected in skin swabs, tissue fragments and internal samples collected from the mummy, and compared them with soil and ice samples gathered at the discovery site in 1991.
The results showed that since 2010, several cold-adapted yeast species have increased in relative abundance while exhibiting lower levels of DNA damage, suggesting that they may retain biological activity and continue to survive under current storage conditions.
According to the study, although the current preservation method suppresses the growth of most microorganisms, it may also support the persistence of certain microorganisms capable of adapting to the storage environment.
The researchers also found that some microbial communities carry genes associated with metabolic pathways required for phenol degradation. Phenol was historically used as a disinfectant in efforts to preserve the mummy.
The finding suggests that some microorganisms may possess the potential to break down biological tissues and may be tolerant of certain disinfection measures.
Otzi the Iceman is a naturally preserved mummy discovered in 1991 in the Alps close to the nowadays borders between Austria and Italy. Research has shown that the remains are more than 5,300 years old.
The mummy has been stored at minus 6 degrees Celsius to replicate the conditions in which it was found. Otzi has provided valuable insights into prehistoric life in Europe, and its long-term preservation has remained a focus of scientific interest. ■