As a writer I try and provide some sort of possible reasoning behind my stories – I feel it makes them more realistic and plausible and the “what if” factor is a great thing to leave with a reader long after they’e finished the book. So that the bacteria that arrive inside the meteor in “The Moon Stealers” could grow and develop quickly I used the presence of high Nitrogen levels in our atmosphere – much higher than the amount of oxygen. But the Moon Stealer bacteria is not too far from the truth, there are organisms already on Earth that use Nitrogen very effectively to survive.
The majority of the animals that inhabit the earth’s surface survive by breaking down oxygen, even though 78% of the air that we breathe is nitrogen as opposed to 21% oxygen. We have evolved in this way because nitrogen is less reactive, and therefore requires significantly more energy to break down. Even though not useful when we inhale, organisms do need nitrogen in other forms as they are the basis of proteins. For this reason nitrogen fixing organisms, such as bacteria and archaea, normally exist in symbiotic relationships with other animals.
In those places where oxygen is unable to penetrate, such as the ocean mud floor, simpler unicellular animals thrive. Bacteria and archaea are single celled organisms with cell walls but no organised nucleus, which are similar in size and structure but with slightly different chemical compositions. They can both adapt to survival in the most extreme conditions, and beneath the mud they do so by breathing nitrogen from their immediate environment. In a process called denitrification, they reduce the oxidised form of nitrogen into dinitrogen gas, while releasing their organic waste.
Until recently it was believed that eukaryotes (more complex life forms with a distinct nucleus in each cell) would be unable to survive under these extreme conditions, because of the lack of oxygen available. Separate samples of ocean mud, which was high in nitrogen content, were collected from several different areas under the sea. Scientists wanted to determine where this high level of nitrogen was coming from. They were quite surprised to discover, after conducting several tests that a single-celled, amoeba like, shelled creature was responsible for the increase in the mud’s nitrogen levels.
Further study revealed that this foraminifer was actually hoarding nitrogen in large amounts. When they realised that there is no symbiotic relationship with bacteria to help the animal absorb the nitrogen, it became obvious that the animal was actually the one breaking down the gas. The breaking down and storing of nitrogen requires a lot of energy, and will only be undertaken by any organism if it is beneficial to them in some way.
Survival is every animal’s first instinct, and each of these microscopic creatures had as much as a month’s worth of breath stored within. Taking the initiative to hoard nitrogen means that this foraminifer has ensured its immediate survival, in the case of an emergency taking place. Since oxygen cannot be stored, these single-celled organisms certainly have the advantage over us as we would expire as soon as the air around us was depleted.