Locked Microbes In Glaciers Could Spark New Pandemics If Released

Surprised scientists have identified more than 900 species of undetectable microbes that live inside glaciers on the Tibetan plateau. Genetic analysis has shown that some have the potential to produce new pandemics if the rapid melting of ice due to climate change frees them from their icy lockups. 

Source: Pixabay

In a new study, researchers from the Chinese Academy of Sciences took ice samples from 21 glaciers in the Tibetan Plateau - a high-altitude point in Asia located between the southern Himalayan mountains and the northern Taklamakan Desert. 

The team then sequenced the DNA of tiny organisms trapped inside the ice, creating a large database of microbe genomes which they named the Tibetan Glacier Genome and Gene (TG2G) catalog. This is the first time that a community of microbes hidden deep within the ice has been genetically monitored.

The researchers found 968 microbial species frozen - mostly bacteria but also algae, archaea and fungi, scientists reported June 27 in the Journal Nature Biotechnology. But perhaps surprisingly, about 98 percent of those species were completely new and unknown to science. 

This level of biological diversity was unexpected due to the harsh conditions associated with living within glaciers, researchers said. "Despite extreme environmental conditions, such as low temperatures,  occasional cracking cycles and limited nutrition, the surface area of ​​glaciers supports biodiversity," the study authors wrote.

Scientists are not sure how old some of these microorganisms are; Previous studies have shown that it is possible to reactivate frozen bacteria for up to 10,000 years, according to the study.

This is not the first time that scientists have discovered an astonishing number of microorganisms in Tibetan ice. In January 2020, a team analyzing ice cores in one ice core found 33 different groups of viruses living in the ice, 28 of which had never been seen before.

You May Also Like: Giant viruses are coming out of melting ice due to global warming

This microbial abundance within the glaciers, coupled with the increase in melting glaciers due to climate change, increases the likelihood that potentially harmful microbes - possibly bacteria - will escape and cause damage, researchers say. "Ice pathogenic bacteria can lead to local diseases and even pandemics" if released into the environment, the authors write.

Evidence suggests that some newly found bacteria may be very harmful to humans and other living things. The team identified about 27,000 virulence factors - molecules that help viruses to invade - within the TG2G catalog. Scientists have warned that about 47% of these virulence factors have never been seen before, so there is no way to know how dangerous these bacteria can be.

Although these pathogenic bacteria do not last long after escaping their glaciers, they can still cause problems, say researchers. Bacteria have the unique ability to exchange large amounts of their DNA, known as mobile genetic elements, with other bacteria. 

So even though glacial bacteria die soon after dissolving, they can still transmit some of their virulence to other bacteria they come in contact with. This genetic interaction between glacier microbes and modern microorganisms "could be extremely dangerous," write scientists.

The Tibetan plateau can be a hot spot for future pandemics as it supplies fresh water to many waterways, including the Yangtze River, the yellow river, and the Ganga river, which supplies two of the world's most populous countries: China. and India. The pandemic quickly spread to densely populated areas, as the world witnessed during the COVID-19 pandemic.

But this great problem will not just impact the continent of Asia. There are more than 20,000 glaciers on Earth that cover about 10% of the planet's land mass, and each glacier may have its own unique microbial communities. In April 2021, a study using satellite imagery found that almost all glaciers on 

Earth showed a rapid rate of ice loss between 2000 and 2019, increasing the risk that pandemics could flee anywhere in the world. Researchers have warned that "potential health risks of these microbes need to be considered" before they can be released from their ice lockups.

 However, there is a silver line in this new study. Genetic records of microbial communities, such as the TG2G catalog, can be used as "tools" for bioprospecting testing - exploring natural systems to discover important new compounds that can be used in medical science, cosmetics and other useful technologies. 

That makes databases such as TG2G even more important, especially if newly found species are extinct in the future; the most likely result is if they are unable to adapt to alternations in their frigid habitat, the scientists wrote.