Scărișoara Cave is the gateway to an underground glacier.Image: IMAGO/Pond5 Images
What lies dormant in the Scărișoara Cave in the Romanian Carpathians holds great opportunities for medicine – and at the same time represents an existential threat to humanity.
Feb 17, 2026, 3:28 p.mFeb 17, 2026, 3:28 p.m
Jannik Sauer / watson.de
The “eternal ice” is a veritable treasure trove for researchers worldwide. The thousands of years of ice layers that are often found in icy caves and landscapes provide a unique glimpse into the past.
What is particularly revealing is what was enclosed in the ice and thereby preserved. Trapped air allows conclusions to be drawn about the composition of the atmosphere at that time. And researchers have also gained new insights in recent decades through discoveries of plant remains, bacteria and the carcasses of prehistoric animals.
This was also the case recently in northwest Romania. There in the Carpathians lies the Apuseni Nature Park, a reserve marked by caves and gorges and home to one of the largest underground glaciers in Europe.
Here – more precisely in the Scărișoara Cave, which gives researchers and tourists access to the huge ice tongue – a team of scientists has now made an astonishing find.
One of the most impressive ice caves in Europe lies in the Romanian Carpathians.Image: IMAGO/Dreamstime
In a 5,000-year-old ice layer, the researchers came across representatives of the bacterial strain Psychrobacter SC65A.3. These microbes are real survivors – they can withstand freezing temperatures and scorching heat and can be brought back to life even after thousands of years.
The trick: Psychrobacter almost completely shut down their metabolism, use special mechanisms to protect themselves from extreme temperatures and even repair their DNA after thawing. This means they can survive in a kind of “hibernation” for thousands of years.
Psychrobacter: Bacteria with amazing antibiotic resistance
And that’s not all: like in a specialist journal “Frontiers in Microbiology” Reportedly, these bacteria are not only extremely resistant, but also immune to many modern antibiotics. Some representatives of these bacteria are dangerous for humans and animals because they can cause infections.
At the same time, their special properties could also serve as inspiration for the development of new antibiotics. The researchers also point this out in their study.
“The bacterial strain shows resistance to several modern antibiotics and carries over 100 resistance-related genes,” explains Cristina Purcarea from the Bucharest Institute of Biology of the Romanian Academy. To test the bacteria’s resistance, the strain was tested for 28 different antibiotics from ten classes used to treat bacterial infections.
The broad resistance discovered poses a real danger. Because of the climate crisis, ice and permafrost are melting around the world, and the bacteria that have lain dormant in them for thousands of years are coming to life. “If melting ice releases these microbes, these genes could spread to modern bacteria and exacerbate the global challenge of antibiotic resistance,” says Purcarea.
But the discovery of the bacteria preserved in the ice also opens up new opportunities. They produce unique enzymes and antimicrobial compounds that have great potential for medicine. “They could inspire new antibiotics, industrial enzymes and other biotechnological innovations,” says Purcarea.
Overall, antimicrobial activity against 14 pathogenic strains was detected, the researchers write. In addition, the bacteria in the strain studied have almost 600 genes with as yet unknown functions – the team hopes to discover novel biological mechanisms here.
“These ancient bacteria are of crucial importance for science and medicine,” says Purcarea. It is now important to handle the discovery carefully and take safety precautions to prevent the bacteria from spreading uncontrollably.