Human microbes can survive on Mount Everest for a long time. American scientists studied soil samples collected at an altitude of almost 8,000 meters above sea level. They found bacteria and fungi adapted to the warm, wet environment of the oral and nasal cavities. Although they remain dormant, this discovery carries an important lesson for … future space explorers.
Microorganisms are present everywhere on Earth, because they perfectly adapt to even extremely unfavorable conditions. According to a study published in the scientific journal “Arctic, Antarctic, and Alpine Research”, bacteria and fungi that prefer moist and warm environments can also survive near the top of the highest mountain in the world.
Signature in the microbiome
The soil samples used in the study were collected at the South Pass (7,906 meters above sea level), which is one of the most popular routes to Mount Everest. Expeditions often set up their last camp here before attempting to reach the summit. Properly secured soil was sent to scientists from the University of Colorado in Boulder, and they analyzed its microbial composition using gene sequencing technology.
The researchers were not surprised to find a wealth of microorganisms. Among the identified species were e.g. genus mushrooms Naganishia, resistant to low temperatures and strong ultraviolet radiation that occurs at these heights. However, they were greatly impressed by the discovery of the DNA of organisms strongly associated with humans, including bacteria of the genus Staphylococcusoccurring on the skin and in the nose and streptococcuscommon in the mouth. Adapted to warm and humid environments, these microbes have proven resilient enough to survive dormant on ‘top of the world’.
“If someone blew their nose or coughed in this area, they could have left a trace like this,” explains Steve Schmidt, the study’s lead author. – The human signature has been frozen in Mount Everest’s microbiome.
Mount Everest and extraterrestrial life
The researchers previously conducted analyzes of samples taken in other cold and inhospitable places, from Antarctica and the Andes to the Arctic. Human-associated microbes did not show up in these places to the extent they were present in the Mount Everest samples. This is related to the heavy tourist traffic at this point in the Himalayas – the South Pass and other points can be places of accumulation of microorganisms, including those transmitted by man.
At high altitudes, microbes are often killed by ultraviolet light, low temperatures and low water availability. Most of them go dormant or die. Researchers speculate that this microscopic addition will have no apparent environmental impact on Everest. But the discovery shows that if humans will one day set foot on Mars or other celestial bodies, they will need to be extra careful.
“We can find life on other planets or moons, we just have to be careful not to contaminate it with our own,” adds Schmidt.
University of Colorado-Boulder
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