Salt-loving microbe grows under combined Mars-like stresses in new lab test

By the Everything Space news desk · 05 Nov 2026 · written from the sources below

Image: Phys.org

The experiment suggests future Mars missions should search for active life, not just ancient biosignatures, in theorized subsurface briny pockets.

Researchers have shown that an Earth microbe can not only survive but actually reproduce under a combination of harsh conditions resembling the Martian subsurface, including low atmospheric pressure, extremely salty liquid, and an oxygen-free, carbon dioxide-rich atmosphere.

The study, led by a University of Florida researcher, used Haloferax volcanii, a microorganism known for thriving in high-salt environments on Earth. The microbe was kept in these stressful conditions for 160 days and was given nitrate or perchlorate to use in place of oxygen for respiration. Cultures without access to either compound stayed alive but did not grow, which helped the team separate mere survival from active reproduction.

Growth occurred, though much more slowly than in matched cultures kept at normal Earth atmospheric pressure. The researchers also noticed the formation of dense biofilms in the low-pressure cultures, which may have helped retain water within the salty solution since these cultures lost little moisture over time.

Earlier research has tested individual Mars-like stresses separately, or exposed organisms to multiple harsh conditions simultaneously but only for short periods. This experiment is notable for combining several stressors over an extended period and demonstrating ongoing biological activity rather than simple endurance.

The lab setup did not capture every feature of the Martian subsurface. The temperature used was far warmer than most of Mars's subsurface, the microbes were fed nutrients by the researchers, and the liquid-water pockets the experiment was meant to mimic have not actually been confirmed to exist on Mars, only theorized.

The findings do not prove that life currently exists on Mars. Instead, they indicate that any native Martian organisms would have had enormous spans of time to adapt to conditions humans consider hostile, meaning such environments might not be inhospitable to life that evolved there. The work could help guide the design of future life-detection missions and inform efforts to prevent Earth microbes from contaminating Mars during spacecraft exploration.

Written in Everything Space’s own words by our news-desk model from the sources above, and checked against them in code: every number in this report appears in its sources, and no sentence is copied from them.