Caray A Walker & Melody Clark
Think of Antarctica, and penguins, seals and whales come to mind. Yet most of its scientific wonders cannot be seen without a microscope: microbial communities that form the foundation of Antarctic ecosystems.
Recent research published in PNAS showed that some microbes in Antarctic soils appear to exist nowhere else on Earth. This challenges scientists' long-held belief that microbes are easily dispersed and found everywhere.
Antarctica is one of the Earth's most isolated and harsh environments. Its organisms face extreme cold, dryness, intense UV radiation and limited nutrients. Soil temperatures range from around 8°C in summer to below -25°C in winter, while air temperatures can fall below -40°C.
Extreme cold also occurs in the Arctic, but it is historical isolation that characterises the Antarctic's evolution. The circumpolar current has kept Antarctic species isolated for 10-15 million years, whereas the Arctic, still highly connected to other continents, has been cold for only around 1.5 million years.
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.
The adaptations that let them survive extreme desiccation, soils with no annual rainfall and prolonged UV-B exposure may have practical applications. Our 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.
Two strains, Psychrobacter and Pseudomonas, inhibited in laboratory tests the growth of clinically important microorganisms, including epidemic methicillin-resistant Staphylococcus aureus, Micrococcus luteus and Candida albicans.
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.
Our laboratory has also monitored human-caused antimicrobial resistance (AMR), which leaves infections untreatable, around the UK's Rothera Research Station on the Antarctic Peninsula. Our study suggests treated wastewater has only a limited effect on surrounding marine microbial communities.
However, in the lab, the bacteria adapted easily to warmer temperatures, suggesting global warming could change these microbes. They may then no longer yield products such as cold-adapted enzymes, which work efficiently at room temperature. Most industrial enzyme reactions demand high energy; introducing cold-adapted versions into large-scale production would cut energy needs and help move us towards net zero emissions.
Antarctic microbes may not draw the attention of penguins, seals or whales, but they are among the continent's most distinctive biodiversity and drive processes those animals depend on. Changes in microbial biodiversity could have consequences far beyond the microbes themselves. Protecting this unseen biodiversity from climate change and human activity is essential to preserve its ecological value and future potential.
Walker is Senior Lecturer in Microbiology, Anglia Ruskin University; Clark is Individual Merit Promotion Scientist, British Antarctic Survey