When we think about Antarctica, many people imagine penguins, seals and whales. However, the majority of Antarctica’s scientific wonders cannot be seen without a microscope. These microbial communities form the foundation of Antarctic ecosystems yet remain largely invisible to most visitors.
Authors
- Caray A Walker
Senior Lecturer in Microbiology, Anglia Ruskin University
- Melody Clark
Individual Merit Promotion Scientist, British Antarctic Survey
Recent research published in PNAS showed that some microbes living in Antarctic soils appear to exist nowhere else on Earth. This challenges scientists’ long-held belief that microbes are easily dispersed and therefore found everywhere.
Antarctica is one of the Earth’s most isolated and harsh environments. Its organisms have to deal with extreme cold, dryness, intense UV radiation and limited nutrients, creating selective pressures unique to the continent. Soil temperatures can range from around 8˚C during the summer to below -25˚C in winter while air temperatures can fall below -40˚C. Rapid temperature fluctuations are common, which creates particularly challenging conditions for life.
While extreme cold also occurs in the Arctic, it is the historical geographical isolation that characterises evolution to the cold in the Antarctic. Antarctic species have been effectively isolated in the cold from the rest of the planet by the circumpolar current for 10-15 million years, whereas the Arctic is still highly connected to other continents and has been cold for only around 1.5 million years .
The researchers studied strains of the bacterium Arthrobacter from Antarctica and compared them with samples from other cold and dry environments, such as the Atacama Desert, Svalbard and the Tibetan Plateau. They found distinct Antarctic strains that seem to have evolved in isolation on the continent, suggesting Antarctica’s conditions have allowed unique microbial communities to develop over
long periods.
The fact that Antarctica may be home to organisms found nowhere else raises important questions about evolution, conservation and biotechnology – and particularly how we can preserve such cold-adapted biodiversity in a warming world.
These microbes are not simply biological curiosities. They play a fundamental role in nutrient cycling and form the base of Antarctic food webs.
Antarctic organisms have evolved remarkable biological solutions to survive conditions that would be destructive to other organisms. They can withstand air temperatures often permanently well below 0°C, extreme desiccation in soils with no annual rainfall and extended exposure to high levels of UV-B in the Antarctic summer .
The same adaptations that allow Antarctic organisms to survive may have major practical applications. For instance, our own research , published in 2025, examined the antimicrobial potential of bacteria cultured from eight Antarctic marine invertebrate species, such as sea cucumbers, sea stars and anemones. We found that two strains of these bacteria (Psychrobacter and Pseudomonas) could inhibit the growth of microorganisms of clinical importance such as epidemic methicillin-resistant Staphylococcus aureus, Micrococcus luteus,and Candida albicans _in laboratory tests.
As well as Antarctica being a potential source of new drugs and enzymes, its isolated geographical location means that it is a protected ecosystem and is often referred to as ” the last great wilderness “. Human activities like tourism and increased scientific activity can risk introducing non-native microorganisms and diseases to Antarctic communities, which have evolved in relative isolation and may lack resilience against introduced organisms.
Recent research from our laboratory monitored antimicrobial resistance (AMR) caused by humans. Affecting both animals and humans, antimicrobial resistance is a global issue that means some drugs which are used to medicate infections no longer work, leaving some infections untreatable. Our research looked specifically at the extent of AMR around the Rothera Research Station (operated by the UK) on the Antarctic Peninsula.
Overall, our study suggests that treated wastewater has only a limited effect on surrounding marine microbial communities.
However, when we grew these bacteria in our lab we saw that the bacteria easily adapted to warmer temperatures, which suggests rising temperatures worldwide could change these microbes. This means they may no longer yield some of the potential products we can take advantage of, like cold-adapted enzymes , which work efficiently at room temperature. The vast majority of industrial and chemical reactions using enzymes often require high amounts of energy to make them work. If we could identify “cold-adapted” versions of these enzymes and introduce them into large-scale production processes, we would reduce our energy requirements and move towards net zero emissions .
Antarctic microbes may not attract the same public attention as penguins, seals or whales but they represent some of the continent’s most distinctive biodiversity. They also drive key ecosystem processes that those popular animals depend upon. Therefore changes in microbial biodiversity may have consequences that extend far beyond the microbes themselves.
Protecting this largely unseen biodiversity from climate change and increasing human activities is essential if we are to preserve both its ecological value and its future potential.
