According to the leading scientists from the Mars Society and other organizations, bacteria are as important to Mars as bacteria in our stomachs or in our medicine or even in our beer, is to us. They played a leading role in the creation of the first ecosystem on Earth and will do so again on Mars. The simple fact is that without bacteria, Mars cannot be terraformed.
Bacteria can be supplied with Carbon, Oxygen, Hydrogen, Nitrogen and Phosphorus, which are the basic components of biochemistry and all are in abundance on the red planet. Carbon can be found within the large supply of carbon dioxide in the atmosphere, oxygen can be found almost anywhere, hydrogen in underground aquifers of water, nitrogen in the Martian soil as well as phosphorus. These should be sufficient amounts to support bacteria and later, plants and animals.
There are many different types of bacteria such as aerobic bacteria that require oxygen to survive, and anaerobic bacteria that can live with or without oxygen. Anaerobic bacteria would have to be used considering how little oxygen is currently present. As well as heterotrophic bacteria that use other organisms for energy, there are also autotrophs that produce their own food through photosynthesis. With the sunlight readily available on the surface, the most efficient candidate would be the autotrophs. By using the Keener Black Chlorophyll theory, black bacteria would be much more useful in that they would absorb more energy than the green ones.
The tasks that the bacteria would have to perform would include pumping water up from underground aquifers by the same way that we drink water upside-down. By releasing diatomic oxygen, the kind that we breathe, into the atmosphere, they would be making mars liveable. We could also pump triatomic oxygen, or ozone, into the atmosphere to help heat the planet, or even a combination of both molecules. The bacteria could also be used to pump other greenhouse gases into the atmosphere and be used in life support to purify water and air.
Bacteria DNA could be manufactured through the use of biological engineering. Scientists would be able to make bacteria divide and grow at a set pace as well as adding a “suicide gene” so that whenever the bacteria reproduced a set number of times, it would simply destroy itself, which would help slow down complete takeover of the planet by bacteria. Scientists would need to make them interlock so as to cling to the rocks, ground, or something else to be able to withstand the dust storms.
Bacteria are the most adaptive and hardy organisms known to man. After the bacteria have been sent to the planet, they will be able to clear the way for another organisms to help in the terraforming of Mars, lichen.