Biosphere Daily Earth Science Environment Repost

Ancient microbes in permafrost

An anthrax outbreak occurred on the Siberian Yamal Peninsula in 2016. This outbreak was the first for 75 years, but it was not from carelessness or terrorism. Instead, it was from long-dead reindeer, frozen into the local permafrost. Temperatures were up, and the permafrost was thawing. When the reindeer carcasses thawed, anthrax spores were released. Twenty people became infected, and one died. This event provides a stark reminder that permafrost doesn’t just freeze dead creatures; it also preserves organisms that still live.

An experiment in 2013 gathered materials from 35,000-year-old permafrost and thawed them under controlled conditions. When the materials thawed, bacteria from a world 35 centuries ago were revived from their long sleep. Then, within one week, they consumed enough organic material to emit half of the available carbon in the sample into the atmosphere as carbon dioxide (CO2). This experiment points towards a developing carbon release system where thawing permafrost in the summer results in an immediate burst of CO2 into the atmosphere. 

The two events described above raise questions about what types of live organisms might awaken from the thawed earth. Viruses and microbes in permafrost come to mind as likely candidates for revival.

Frozen Viruses

High in the Tibetan mountains, on the roof of the world, lies the Guliya ice cap. Samples from this ice cap were recently analyzed for viruses. In a single-core sample of ice from 15,000 years ago, the researchers identified 28 unknown genera of viruses. The word genera is the plural of genus, and a genus contains a group of similar species. For example, the genus Homo includes both modern human beings and Neanderthals. Also, some scientists argue that chimpanzees should be included in this genus. Granted, the world of viruses and microbes is huge, but 28 new genera in one ice core seems a bit unnerving.

The recognition of live viruses and microbes in both glaciers and permafrost raises the possibility that pathogenic organisms will awaken when the ice thaws. The Siberian anthrax outbreak is a case in point. Even though anthrax exists today, other pathogens from up to 50 centuries ago may have passed out of existence, only to return as thawing unleashes them.

However, the news is not all gloomy. Some scientists are also mining the microbes in permafrost in search of medicinal or even commercial uses. 

How do they survive?

The first thing to be said is that survival for centuries in ice is a neat evolutionary adaptation. Your species then has a mechanism allowing apparent extinction, followed by a dramatic rise from the dead. Researchers at the University of California in Berkley estimate that some microbes can survive in a deep freeze for 100,000 years. 

This reincarnation trick is enabled by a thin film of liquid water that envelops the microbe as it enters a deep freeze. This process facilitates the diffusion of gases from nearby air bubbles into the water film, thus giving the microbe access to hydrogen, oxygen, methane, and other gases. It seems a meager food source, but apparently, it is enough to keep the bacteria alive in hibernation mode. 

Viruses are different that cellular microbes, and they occupy a fuzzy space on the edges of life. The virus consists of genetic material wrapped in a protein shell. So, they have no metabolism or energy needs. For them, hanging out in deep freeze is not much different than hanging out anywhere else. Preservation in ice seems like a normal fit.

The bottom line is that microbes do survive over vast spans of time in icy tombs, and as the ice thaws, they awaken from their long slumber. Whether these microbes in permafrost are generally beneficial or detrimental remains to be seen.


Virus survival strategies (Source: ArcheanWeb) –  Also:

Permafrost: A ticking carbon bomb (Source: ArcheanWeb) – Also:



Microbes can survive ‘deep freeze’ for 100,000 years (By Maggie Mckee and Daniele Fanelli; NewScientist) –  Also:

15,000-Year-Old Viruses and Bacteria Found in Glacier Ice from Tibet (By Natali Anderson; Science News) –  Also:

Feature Image: Neutrophil engulfing anthrax bacteria  (Modified) –  By Volker Brinkmann – (November 2005). “Neutrophil engulfing Bacillus anthracis”. PLoS Pathogens 1 (3): Cover page. DOI:10.1371. Retrieved on 2009-01-04., CC BY 2.5,

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.