Interactions
Cyanobacteria usually interact with its environment by fixing nitrogen from its surroundings into a usable form. The cyanobacteria are not able to use the original form of nitrogen in the atmosphere because of the chemical structure of nitrogen gas. Arthrospira platensis is not able to fix nitrogen because they lack the heterocysts that make it possible to do so.
Most cyanobacteria produce a chemical signal that tells them to form hormogonia. They also serve as chemo attractants which guide these hormogonia into the different plant tissues.
Unfortunately for A. platensis, there aren't many organisms that can survive in such an alkaline environment. This makes it hard for the cyanobacteria to have many outside interactions with other organisms.
Let's take a look at some fun facts about spirulina!