Martian colonizers can grow certain cyanobacteria using local resources available on the planet.

We cannot ship all our food and oxygen from Earth. It is too expensive. Instead, we can use local biological systems. Certain cyanobacteria can grow directly on Mars. They use the abundant carbon dioxide, sunlight, and atmospheric nitrogen. These tiny organisms can produce food, fuel, and oxygen, laying the groundwork for a self-sustaining outpost.