Pioneer Labs' Mars microbe may build a city, lab suggests

Space.com reports that Pioneer Labs, a nonprofit biotech startup in Emeryville, California, has engineered a microbe named sPL.001 that can grow on simulated Martian dirt, water and air. The microbe makes bioplastics, the same material family behind compostable cups and 3D printing filament, which could be used to build habitats on Mars.

The company's pitch is that future Mars crews should live off the land instead of waiting for supply ships. Space.com notes that nearly 50 robotic missions have gone to Mars since 1960, and crewed flight remains a priority for national space agencies and private companies. The long shot is terraforming: turning the cold, arid planet into one that supports Earth life. Pioneer Labs calls the microbe a safe first step.

"On Mars, nature will do the same jobs for us that she does on Earth: create fertile soil, shelter, oxygen and food," CEO Erika DeBenedictis told Space.com.

Martian soil is the obstacle. It holds useful raw materials, but they are mixed with perchlorate and salts that make growth difficult for most organisms. Older ideas include washing the poisons out, bringing fertilizer from Earth, or skipping the soil with hydroponics. Pioneer Labs argues those approaches don't scale well in time or expense.

Instead, the team took Earth microbes that could already make bioplastics and slowly exposed them to Mars-like conditions. "It wasn't obvious this was going to work," DeBenedictis said. "The first time we tested growth of terrestrial microbes in Mars conditions, none of them grew!" Eventually, the microbes evolved tolerance for Martian toxins. "It was so cool to see these microbes start growing better on simulated Mars nutrients," she said. "Life finds a way!"

Safety is built into the design. The microbe needs a stirred, heated bioreactor to handle Mars' cold, radiation and thin atmosphere. It needs nitrogen delivered as acetate, because Martian air has too little nitrogen for it to use. It isn't photosynthetic. Pioneer Labs suggests those limits make it unable to survive outdoors on Mars, reducing the risk of contaminating the planet or any native life that might exist in underground aquifers or ancient salt crystals.

Pioneer Labs says sPL.001 is the first of five organisms needed to make Mars green. In one study, the team estimated that a single rocket could carry everything needed to set up a Mars city. Samuel McKee, a University of Reading scientist who studies DNA repair, told Space.com he found it believable that the microbe wouldn't accidentally terraform Mars. "Many adapted or edited microbes on Earth do not survive outside of a fixed environment despite their evolution, or without a certain food supply," he said.

DeBenedictis offered the usual Mars caveat: simulated dirt isn't the real thing. "We reconstructed the relevant chemistry of Martian regolith as carefully as we could from high-quality rover data from multiple locations on Mars. But ultimately, the real test will be doing this with actual Martian regolith," she told Space.com.

McKee added that the gene-editing work could help with climate change and extreme habitats on Earth. "We will be watching with anticipation when these microbes are finally launched to the Martian surface," he said.

• bioplastics
• Erika DeBenedictis
• Mars
• Pioneer Labs
• sPL.001
• terraforming