Macro view of a gel plate with microbe colonies glowing violet and magenta in the dark, next to a half-open radiation-shielding chamber door lit by a thin magenta light.
Life Support

Vitamins With a Radiation Shield: Microbes on the Road to Mars

Expired before arrival. Vitamin pills have a shelf life, and a round trip to Mars lasts years. Bioengineer.org, reporting a study in iScience, notes that vitamin supplements degrade during long storage in spaceflight. « [S]cientists are exploring in situ microbial production as a complementary strategy, » explains Bioengineer.org, « in situ » meaning on the spot. In plain words: brew vitamins on board, using microbes.

A stress test, with radiation. Three food-grade microbes, tied to the European Space Agency’s MELiSSA life-support programme, spent seven days under gamma rays, high-energy radiation standing in for the space kind. Dose rates included 22 microgray per hour (a unit of absorbed radiation energy), against about 9 on Mars’s surface. A yeast and a spore-forming bacterium, one that waits out danger inside a tough shell, shrugged it off: same growth, same vitamin B2. Mars-bound microbes may also have to clear a risk test before working on Mars.

One Microbe Blinked, Its Vitamins Didn’t

A woman in profile draws a sample with a pipette from a glass bioreactor aboard a spacecraft, a porthole behind her showing a small red Mars lit by amber sunlight.

The one that flinched. The third microbe, a lactic acid bacterium found in the gut, struggled. Its biomass, the living matter in the culture, shrank as the dose rose, and it took longer to restart growing. Yet its vitamin output per unit of biomass held steady. It diverted resources to repairing its DNA, like a crew patching the hull before cooking dinner.

Not so fast. The authors list limits. Cobalt-60, the radioactive source behind the gamma rays, does not reproduce full cosmic radiation. Tests ran on gel plates, not in the liquid bioreactors (growth tanks) planned for spacecraft, and seven days is short. « The experiments were run under standard laboratory gravity, » explains Bioengineer.org, so weightlessness is untested. These microbes can take the trip’s radiation; whether they can cover a crew’s vitamins for years remains open.

[Co-produced by Ludovic Nachury and an AI agent with a defined editorial voice and visual style. Illustrations are AI-generated. Sources are cited, and each article is checked by a human before it goes live. How this works.]

Votre commentaire