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Baffled scientists have discovered more than 900 never-before-seen species of microbes living in glaciers on the Tibetan Plateau. Analysis of the microbes’ genomes revealed that some have the potential to spawn new pandemics if the rapid meltdown caused by climate change frees them from their frigid prisons.
In a new study, researchers from the Chinese Academy of Sciences took ice samples from 21 glaciers on the Tibetan Plateau — a high-altitude region in Asia sandwiched between the Himalayan Mountains to the south and the Taklamakan Desert to the north. The team then sequenced the DNS of the microscopic organisms trapped in the ice and created a huge database of microbial genomes, which they called the Tibetan Glacier Genome and Gene Catalog (TG2G). It is the first time that a microbial community buried in a glacier has been genetically sequenced.
The team found 968 species of microbes frozen in the ice – the most bacteria but also algae, archaea and fungi, the researchers reported on June 27 in the specialist journal natural biotechnology (opens in new tab). But perhaps even more surprising was that around 98% of these species were completely new to science. This level of microbial diversity was unexpected because of the challenges associated with life in glaciers, the researchers said. “Despite environmental extremes such as low temperatures, intense sunlight, freeze-thaw cycles, and nutrient limitations, glacier surfaces support a diverse spectrum of life,” the study authors write.
Researchers aren’t sure exactly how old some of these microbes are; Previous studies have shown that it is possible to revive microbes trapped in ice for up to 10,000 years, according to the study.
This isn’t the first time scientists have found a surprising abundance of microbes living in Tibetan glaciers. In January 2020, a team analyzing ice cores from a single glacier discovered 33 distinct groups of Viruses that live in ice28 of which have never been seen before.
The surprising microbial diversity in glaciers, coupled with an increase in melting glacial ice due to climate change, increases the likelihood that potentially dangerous microbes – most likely bacteria – will escape and wreak havoc, researchers said. “Pathogenic microbes trapped in ice could lead to local epidemics and even pandemics” if released into the environment, the authors write.
There is evidence 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 to invade and colonize potential hosts – within the TG2G catalogue. The researchers warn that about 47% of these virulence factors have never been observed before, so there’s no way of knowing how harmful the bacteria might be.
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Even if these potentially pathogenic bacteria don’t survive long after escaping their glaciers, they can still cause problems, the researchers said. Bacteria have the unique ability to exchange large parts of their DNA, called mobile genetic elements (MGEs), with other bacteria. So even if the glacial bacteria die off shortly after thawing, they can pass on some of their virulence to other bacteria they encounter. This genetic interaction between glacial microbes and modern microbes “could be particularly dangerous,” the scientists write.
The glaciers of the Tibetan Plateau could be a hot spot for triggering future pandemics, as they supply freshwater to a number of waterways, including the Yangtze, Yellow River and Ganges, which feed two of the world’s most populous countries: China and India. Pandemics spread quickly in densely populated areas, like the world during the COVID-19 Pandemic.
But this potential problem isn’t unique to Asia. There are more than 20,000 glaciers Earth They cover about 10% of the planet’s landmass, 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 showed accelerated ice loss between 2000 and 2019, increasing the risk that pandemic microbes could escape anywhere in the world. The researchers warned of the “potential health risks [of these microbes] must be evaluated” before being released from their freezing prisons.
However, this new study has a silver lining. Genetic records of microbial communities, such as the TG2G catalogue, could be used as “toolkits” for bioprospecting – the study of natural systems to find valuable new compounds that can be used in medicine, cosmetics and other useful technologies. This makes databases like TG2G very important, especially if the newly discovered species become extinct in the future; an outcome all too likely if they fail to adapt to changes in their frozen habitat, the researchers wrote.
Originally published on Live Science.
Never-before-seen microbes locked in glacier ice could spark a wave of new pandemics if released Source link Never-before-seen microbes locked in glacier ice could spark a wave of new pandemics if released