RE: Fungi Terraforms Planets
Alvin Eriol > August 11th, 2021, 09:05 PM
Most sci-fi treatments of "seeding" planets to terraform them IIRC involved yeasts and/or algae. Earth itself was to a large extent "terraformed" when blue-green algae evolved and spread. Like the more sophisticated photosynthesizing autotrophs that followed later, the blue-green algae obtained carbon from the once-abundant carbon dioxide of the Earth's early atmosphere. The abundant algae eventually changed the atmospheric composition to be rich in oxygen that was useless and poisonous to the algae and to the primitive heterotrophs (similar to the botulism bacteria) whose metabolism is a kind of fermentation that yields methane. This event is called by various names such as the Great Oxygen Crisis, and resulted in an atmosphere we and Terran higher animals can actually breathe.
Presumably as we'd want to terraform planets and not necessarily Mercuryform or Jupiterform or Lunaform them, we'd be seeking planets similar to primitive Earth in its 1st half billion yrs or so, and seed them with organisms tailored to produce organic substrate and oxygen, along with perhaps spores of other organisms able to metabolize oxygen once the atmosphere changes. A long time later, a more-or-less habitable planet suitable for finishing up terraforming and human colonization could result. That's another scenario Larry Niven wrote a number of stories about.
Just actually read the article Doc Tony linked. Fascinating! Sounds like fungi would definitely have multi functions in such projects!