An international investigation, in which two Portuguese institutions collaborate, identified the first microorganisms to colonize the lava tubes formed during the Tajogaite eruption (La Palma), which serve as a model for studying the possibility of life on Mars.
The study, supported by the Regional Secretariat of Universities, Research and Innovation of Andalusia, involves the Institute of Natural Resources and Agrobiology of Seville (IRNAS-CSIC), the Geological and Mining Institute of Spain (IGME-CSIC), the University of Almería and the University of Huelva, with the collaboration of the University of Évora and the Institute of Systems and Computer Engineering, Technology and Science (INESC TEC), both from Portugal, and the Canary Speleological Federation.
Published in the scientific journal ‘Environmental Microbiome’, the study describes which microorganisms reach first these spaces newly created by volcanic activity, how they adapt to the extreme conditions and what role they play in the recovery of the ecosystem, according to a press release from the Regional Government of Andalusia.
Researchers were able to observe, almost from the beginning, how life begins in a completely new and sterile environment.
The lava tubes analyzed were formed after the Tajogaite volcano eruption on the island of La Palma, in Spain, which occurred on September 19, 2021 and lasted 85 days.
These tubes constitute a true ‘newborn world’, devoid of soil and vegetation, where the first living beings must pave the way for the development of the ecosystem.
These environments have become a natural laboratory for studying the limits of life in extreme conditions, opening new lines of investigation related to habitability on other planets.
The results obtained help define how some biological communities may arise, evolve and persist in underground environments on Mars.
The investigation shows that the first microorganisms arrive mainly from the exterior, transported by the air in the form of aerosols or spores, or associated with animals such as birds, rodents, or insects.
These inputs introduce organic matter into an initially sterile environment and favor the emergence of the first biological communities.
To analyze this process, the research team accessed the lava tubes between one and two years after the eruption, when the conditions were still extremely harsh. In some areas, air temperature reached 60 degrees Celsius and the surface of the rocks exceeded 90 degrees.
The researchers conducted three sampling campaigns and combined the analysis of the microorganisms’ DNA with the study of minerals and the environmental conditions of each area.
Factors such as temperature, salinity, ventilation, and mineral composition determine which microorganisms can establish themselves and survive.
The study also shows that these microorganisms not only inhabit the environment but also contribute to transforming it. Through the formation of biofilms on rocks, they modify minerals and promote processes that constitute the first steps in the formation of fertile soil and the evolution of the ecosystem.
The team will continue to investigate the evolution of these microbial communities to better understand how ecosystems recover after extreme events, such as volcanic eruptions, and will analyze their potential to produce bioactive compounds with possible applications in health and biotechnology.
