For over 15 years, biochemist Sébastien Fontaine has been investigating the resilience of soil, specifically its ability to release carbon dioxide even after being sterilized. His team at the French National Institute for Agriculture, Food, and Environment sealed soil samples in jars and subjected them to gamma radiation to eliminate all microbial life. Surprisingly, the soil continued to emit carbon dioxide, indicating ongoing metabolic activity.
Fontaine’s research, detailed in a 2025 paper published in Science Advances, demonstrates that these soil samples consumed oxygen and released carbon dioxide for an astonishing six years. This finding raises questions about the nature of metabolic processes, suggesting they may not be exclusive to living organisms. Fontaine posits that such biochemical reactions could predate life itself on Earth.
The Experimentation Process
Initially, Fontaine aimed to establish a baseline for carbon emissions in lifeless soil. Using a sterile syringe, his team periodically sampled air from hermetically sealed jars and measured carbon content with a mass spectrometer. After the radiation treatment, carbon emissions declined but remained stable for over 100 days. Despite skepticism from peers, Fontaine persisted in exploring the metabolic processes occurring in the sterilized soil.
To further investigate, the team introduced enzymes extracted from yeast cultures, which resulted in a spike in carbon emissions. This led them to hypothesize that metabolic-like reactions were occurring in the absence of life. Over the next decade, they conducted rigorous tests to confirm the sterility of their samples, employing additional radiation, pressure, and heat treatments, yet the soil continued to exhibit carbon emissions.
Long-Term Observations
From 2018 onwards, Fontaine’s team, including researcher Clémentin Bouquet, studied two sets of irradiated soil samples—one regular and one supplemented with glucose. After 1,606 and 2,442 days, the samples still emitted carbon dioxide, with glucose-augmented samples showing higher rates. This reinforced the idea that nonbiological catalysts in soil could facilitate reactions akin to metabolic processes.
Fontaine developed a fuel cell to detect electron flow through the soil, demonstrating a current significantly higher than that of a control setup. This suggested that sterile soil could support electron flow indicative of reactions similar to the Krebs cycle, traditionally thought to require cellular conditions.
Implications for the Origin of Life
Fontaine’s findings align with emerging theories about the origins of life, suggesting that metals in soil may catalyze biochemical reactions. While some researchers argue that enzymes from dead cells could still be active, Fontaine maintains that the long-term emissions observed are unlikely to stem from enzyme activity alone.
As Fontaine and his colleagues continue to explore the biochemical capabilities of soil, they highlight the potential for processes that may predate life itself, suggesting that even in familiar environments, we may overlook significant biochemical phenomena. This research opens new avenues for understanding the origins of life and the fundamental processes that govern biochemical reactions.
This article was produced by NeonPulse.today using human and AI-assisted editorial processes, based on publicly available information. Content may be edited for clarity and style.
