Nitrogen fixation microbes that have an out sized impact on our world through their role in translating atmospheric nitrogen into chemical forms that plants can actually use. Nitrogen is essential to making amino acids and nucleic acids, and those are important things. So if all the nitrogen in the world were to disappear in an instant, we would not have protein. we would not have DNA. We wouldn't have the fundamental building blocks that make life on this earth possible. The problem is that nitrogen gas is diatomic nitrogen. Its hard for your bodies to break the bonds between those nitrogens and convert them into forms we need, which is why we need to eat other animals and plants that have nitrogen. but plants have the same problem as us. They can't turn all that nitrogen in the atmosphere into forms that they can use.