Dr. Friedmann expects that new special microorganisms will be developed by genetic engineering to do the job of creating soil on Mars. Even if the Chro-o we know on Earth is actually used as the basic life form, it will then be a vastly improved version of today's simple microbe. The hero of our story is a little tiny bacteria called Chroococcidiopsis. It is a very simple creature that can live almost anywhere under all sorts of conditions. There are many different kinds of bacteria.
Bacteria are quite tough and can live just about anywhere.
A fungus may look like a plant, but the microorganisms called fungi are more closely related to animals. Many fungi get their nutrients directly from soil, while others feed on dead plants and animals. Mushrooms we buy at the food market are a fungus you can eat. Fungi come in many sizes and forms, and some have important uses to humans. Yeasts are very tiny fungi that we use to bake bread.