Microbial Life In One Of The Most Extreme Ecosystems On Earth: The Antarctic Plateau

An international team led by the Centro de Astrobiologia (CAB), CSIC-INTA, and the Universidad Autónoma de Madrid, shows a novel platform for scientific exploration of the most remote places in Antarctica, a mobile and versatile scientific base that allows the development of cutting-edge science with minimal environmental impact.

Thanks to the WindSled, they described microbial life from the air and down to 4 m deep in the ice of the most inhospitable place on Earth. The authors decipher where Antarctic bacteria come from, as well as the bacterial communities trapped in the snow/ice cover over the last 40-50 years.

The Antarctic Plateau, a vast expanse of ice and snow more than 3000 m above sea level, is one of the most extreme environments on Earth. It has recorded the lowest temperature (-89.2ºC, although it is estimated that it can reach -93.2ºC), and at the same time one of the places on Earth with the lowest precipitation record and the most arid.

Low temperature and absolute humidity, together with high UV radiation during the summer, scarcity of liquid water and scarcity of nutrients, make the Antarctic Plateau an excellent natural laboratory for investigating the extremes of life on Earth. “This environment is perhaps the best terrestrial analog for studying the possibility of life on other worlds, such as the icy moons Europa (Jupiter) and Enceladus (Saturn), or the large icy areas of the planet Mars.

This makes the Antarctic Plateau an ideal place to develop instrumentation for astrobiological purposes, such as the “Life Detector Chip or LDChip” says Professor Victor Parro, INTA researcher at Centro de Astrobiologia (CAB), INTA-CSIC.

Route and prevailing winds in the days prior to sampling during the Wind Sled antarctic campaign. – -CAB

However, logistical constraints, cold, remoteness and altitude make it difficult to access the Antarctic Plateau for sampling and in situ studies. It is considered the last pristine environment on Earth, where wind, as a means of transporting deposited particles, has been proposed as the main cause of input and distribution of life, nutrients, as well as pollutants. The use of heavy vehicles, with combustion engines, is expensive, polluting, inefficient and logistically complex to travel long distances.

“The WindSled offers unique features for scientific exploration of large expanses of ice or snow: large capacity for both crew (4-5 people) and scientific-technical cargo (>500 kg of equipment), robust (easy to repair), highly versatile, safe and reliable (modular and scalable), and zero emissions in their travels,” explains Spanish explorer Ramón Larramendi, creator and developer of WindSled.

During the 2018-2019 campaign to the Antarctic Plateau, four well-trained crew members traveled 2,538 km across the western sector of the Antarctic Plateau, from the vicinity of Novolazarevskaya Station to Fuji Dome (>3,500 m altitude). The WindSled carried 200 kg of scientific instrumentation to perform multiple in situ scientific sampling and experiments, including detection of microorganisms using a portable immunosensor (LDChip) designed for life detection in planetary exploration, a collector of aerosols and biological material from the air capable of operating in the extreme conditions of the expedition, and continuous monitoring of possible deliquescence events along the transect.

WindSled in Antarctica — CAB

“This work demonstrates the value and importance of using relatively inexpensive, emission-free sampling platforms in even the most remote locations in Antarctica, where in situ observations are lacking, but which are essential for understanding current climate change and predicting future climate change and its impacts,” says Professor Mayewski, director of the Climate Change Institute at the University of Maine, USA, and co-author of the paper.

The ice of the Antarctic Plateau represents an archive of past climatic and atmospheric events, as well as the historical presence and accumulation of biological material. Until now, few studies have focused on the microbiology of the high Antarctic Plateau, and those that have done so have only explored surface snow up to 30 cm deep. “We describe the first microbial profile from air to 4 m depth of snow/ice on the Antarctic Plateau at three significantly distant locations, deciphering the bacterial communities trapped in snow/ice from the last 40-50 years.

This is the first time that microorganismshave been collected and identified from the air on the Antarctic Plateau,” says Prof. Antonio Quesada, Universidad Autónoma de Madrid. “It is not only the first time that samples of the microorganisms that circulate in the air of this immense territory of the planet have been obtained, but also the first time that the new collectors and the statistical instrument that we have had to invent to understand their origin have been used,” explains Prof. Ana Justel, Universidad Autónoma de Madrid.

The Antarctic Plateau is also one of the driest places on Earth. The combination of extreme cold and dryness makes it an analogous environment to Mars, where the average annual surface temperature near the equator is -58°C and the atmospheric water vapor content is near negligible. As on Mars, the water on the Antarctic Plateau is physically in a frozen or vapor state, but rarely in a liquid state. “WindSled allows us to go into the most remote places in Antarctica and study under what conditions liquid water can form in an icy desert, for example, through the deliquescence of certain salts, to understand similar processes on Mars. We have shown that in certain instances along the more than 2500 km traveled such deliquescence phenomena are possible, and could provide water to maintain minimal biological activity. Perhaps similar phenomena could occur in some regions of Mars,” says Dr. Alfonso F. Davila, a researcher at NASA’s Ames Center in California.

A Itinerary showing the locations where the two set of samples were collected: red circles named N, M and S, for three cores for geochemical and microbiological studies; and yellow stars (a–f) for six oxygen and hydrogen isotope analysis core samples (see Fi. 2). B the WindSled mobile platform consisting of three modules (driving, payload, and living room) and wind-powered by a 200 m2 kite. C Drilling system and the aspect of the 1 m snow/ice cores. D Airborne aerosol collector in the field and scheme: 1, manifold pipe; 2, turbine; 3; sample holder; 4, Fan 9GT0612P4G001; 5, collector support; arrow, flow direction (see Materials and Methods for further details). E Five-day back-trajectories of the air parcels from the collected samples on the African sector of the East Antarctic Plateau. Grey contour lines indicate altitude at 500 m intervals. The depicted back-trajectories originate from the three distinct sampling points: N (red), M (green) and S (blue). These trajectories are computed at 25%, 50%, and 75% of the boundary-layer height with hourly initialization the sampling periods. — CAB

Transport vectors, such as snow/ice particles and windblown bioaerosols, can condition the biogeographic distribution of the bioburden, depending on the prevailing winds, as demonstrated by the authors of this work. The use of the LDChip biochip to detect traces of life during the campaign made it possible to detect the presence of certain microorganisms, including cyanobacteria, in ice core samples. “This is a further demonstration of the great LDChip’s ability to search for life in planetary exploration,” says Dr. Mercedes Moreno, researcher of the INTA’s SOLID-LDChip team at the CAB. Once in the laboratory, a new species of cyanobacteria of the genus Gloeocapsopsis was isolated and cultured from one of the core samples of between 3 and 4 m depth, with an estimated age of 30-40 years. It is like “traveling back in time” and rescuing biological material, still viable, that was deposited decades ago. The deeper the sample, the greater the age. The viability of microscale deliquescence phenomena suggests that in certain microenvironments, e.g., salt crystals transported from shore and deposited on ice, or aerosols with concentrated biological material, minimal metabolic activity may be taking place to keep some microorganisms alive.

Undoubtedly, the WindSled wind sled is a truly mobile, zero-emission scientific platform with large payload and crew capacity, enabling unprecedented and planet-friendly research on the unexplored Antarctic Plateau and other large ice masses. Using the Wind Sled on a regular basis on the world’s frozen plateaus could mean access to barely studied ecosystems, putting our researchers at the forefront of the study of the cryosphere.

About CAB

Centro de Astrobiología (CAB) is a joint research center of the National Institute of Aerospace Technology (INTA) and the National Research Council (CSIC) of Spain. Created in 1999, it was the world’s first center dedicated specifically to astrobiological research and the first non-US associate member of NASA’s Astrobiology Institute (now the NASA Astrobiology Program). It is an interdisciplinary research center whose main objective is to study the origin, presence and influence of life in the universe from a transdisciplinary approach. In 2017, CAB was distinguished by the Ministry of Science and Innovation as “María de Maeztu Unit of Excellence”.

CAB has led the development of the REMS, TWINS and MEDA instruments, all operational on Mars since August 2012, November 2018 and February 2021, respectively; as well as the science of the RLS and RAX Raman instruments, which will be launched in this decade on board of ExoMars and MMX missions. In addition, CAB develops the SOLID instrument, aimed at the search for life in planetary exploration. Likewise, CAB participates in different missions and instruments of great astrobiological relevance, such as CARMENES, CHEOPS, PLATO, BepiColombo, DART, Hera, the MIRI and NIRSpec instruments at JWST and the HARMONI instrument at ESO’s Extremely Large Telescope (ELT).

Scientific paper published in Nature Communications: Microbial biogeography along a 2578 km transect on the East Antarctic Plateau (open access)

Reference and doi: https://doi.org/10.1038/s41467-025-55997-6

Astrobiology