Also:

  The new term introduced by the researchers for this type of coexistence, "alcobiosis," is formed by letters from the three key words: algae, corticioid fungi and symbiosis.

I prefer falgosis, but... whatever.

Also:

  "And so the main unknown still is in what way this symbiosis is beneficial for each of the partners."

It's probably immune system--as in the algae help the funghi fend off predators/pathogens; or, binding, as in the algae secrete a substance that makes it easier for the funghi to attach to or burrow through the surfaces.