Blue serpentinite mud from a newly discovered mud volcano.
They are fats, coming from living organisms of unknown identity. They were close to the mysterious Mariana Trench, almost 3000m deep. “Life may have emerged precisely in places like this.”
Unexpected signs of life have been discovered in samples of a mysterious blue, viscous substance collected from mud volcanoes near , almost 3,000 meters deep.
The samples, taken during an expedition aboard the research vessel R/V Sonne in 2022, revealed the presence of fats from unknown living organisms: These are signs of microorganisms that can survive in conditions considered extreme.
The material, with an extremely high pH of 12 — one of the highest recorded in natural ecosystems — is so alkaline that would cause serious burns in contact with the skin. But the international team of researchers, according to , confirmed that some species of extremophile microbes thrive in this environment, according to the study in Communications Earth & Environment.
“We believe that primordial life may have arisen precisely in places like this,” said organic geochemist Florence Schubotz.
Geoscientists analyzed two of the nine sediment cores collected, including one from the “Pacman” volcano, composed mainly of serpentinite and brucite fragments, minerals that maintain their intense blue color because they are almost isolated from seawater. In the upper layers, closer to the ocean floor, the color becomes blue-green, due to the dissolution of minerals in contact with salt water.
Inside the serpentinites, researchers detected lipids from the cell membranes of bacteria and archaea, essential for resisting highly alkaline environments. The preservation of these molecules indicates the existence of active microbial communitiesadapted to extreme conditions and dependent on chemical processes to generate energy. These microorganisms use methane and consume sulfate, releasing hydrogen sulfide — a corrosive compound — in a process comparable to plant photosynthesis.
According to Schubotz, until now the presence of methane-producing microorganisms in this type of system had only been assumed, but this is the first direct confirmation. The team highlights that underground life represents around 15% of Earth’s total biomass and plays a crucial role in global nutrient cycles.
Scientists hope that studying these microorganisms will help to better understand how life may have emerged in inhospitable environments on early Earth — and, perhaps, on other planets.
