(ORDO NEWS) — Scientists have discovered more than 900 never-before-seen types of microbes living inside glaciers in the Tibetan Plateau.
The analysis of the genomes of these microbes has shown that some of them are capable of creating new pandemics if the rapid melting caused by climate change releases them from their ice prisons.
In a new study, scientists from the Chinese Academy of Sciences took ice samples from 21 glaciers in the Tibetan Plateau, a high mountain region in Asia sandwiched between the Himalayan mountain range to the south and the Taklamakan desert to the north.
The team then sequenced the DNA of the microscopic organisms trapped in the ice, creating a massive microbial genome database they called the Tibetan Glacier Genome and Gene Catalog (TG2G). This is the first case of genetic sequencing of a microbial community hidden in a glacier.
The team found 968 species of micro-organisms frozen in ice – mostly bacteria, but also algae, archaea and fungi, the researchers reported June 27 in the journal Nature Biotechnology (opens in a new tab).
But perhaps more surprisingly, about 98% of these species were completely new to science. This level of microbial diversity was unexpected due to the difficulties associated with life inside glaciers, the researchers say.
“Despite extreme environmental conditions such as low temperatures, high levels of solar radiation, periodic freeze-thaw cycles and lack of nutrients, diverse life is supported on the surface of glaciers,” the authors of the study write.
Researchers don’t know exactly how old some of these microbes are; previous research has shown it is possible to revive microbes that have been trapped in ice for 10,000 years, the study says.
This is not the first time that scientists have discovered a surprising abundance of microbes living in Tibetan glaciers. In January 2020, a team analyzing ice cores from one glacier found 33 different groups of viruses living in ice, 28 of which had never been seen before.
The amazing microbial diversity in glaciers, combined with increased melting of glacial ice due to climate change, raises the possibility that potentially dangerous microbes – most likely bacteria – will break out and wreak havoc, the researchers say.
“Pathogenic microbes in the ice shell can lead to local epidemics and even pandemics” if they get into the environment, the authors write.
Evidence suggests that some of the newly discovered bacteria could be very dangerous to humans and other organisms.
The team identified 27,000 potential virulence factors – molecules that help bacteria invade and colonize potential hosts – in the TG2G catalog.
About 47% of these virulence factors have never been seen before, so there is no way to know how dangerous these bacteria can be, the researchers warned.
Even if these potentially pathogenic bacteria don’t survive long after emerging from glaciers, they can still cause problems, the researchers say.
Bacteria have the unique ability to exchange large portions of their DNA, known as transposable genetic elements (MGEs), with other bacteria.
So even if glacial bacteria die shortly after thawing, they can still transfer some of their virulence to other bacteria they encounter.
This genetic interaction between glacier microbes and modern microorganisms “may be particularly dangerous,” the scientists write.
The Tibetan Plateau’s glaciers could be a flashpoint for future pandemics as they feed fresh water to a number of waterways, including the Yangtze, Yellow and Ganges rivers, which supply two of the world’s most populous countries: China and India.
Pandemics spread rapidly through densely populated areas, as the world has witnessed during the COVID-19 pandemic.
But this potential problem will affect more than just Asia. There are more than 20,000 glaciers on Earth, covering about 10% of the planet’s land area, and each glacier likely has its own unique microbial communities.
In April 2021, a study using satellite imagery of glaciers found that almost every glacier on Earth is showing accelerated rates of ice loss between 2000 and 2019, increasing the risk that pandemic-causing microbes could travel anywhere planets.
The researchers warned that “the potential health risk [of these microbes] must be assessed” before they are released from their ice prisons.
However, there is also a positive side to this new study. Genetic records of microbial communities, such as the TG2G catalog, can be used as a “toolkit” for bioprospecting – the study of natural systems in order to find new valuable compounds that can be used in medicine, cosmetics and other useful technologies.
This makes databases like TG2G very important, especially if newly discovered species become extinct in the future, which is likely if they cannot adapt to changes in their frozen habitat, the researchers write.
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