[leducw]

There was a short story I recall reading a while ago where there was a release of such a bacteria and it told the story about how that release screwed up the world slowly as it spread. Can't for the life of me find it however.

[jaggederest]

Ringworld, for one example. Society build on unobtanium dies when a microbe learns to digest it.

[njarboe]

More accurately is that the society was destroyed when a fungus was introduced by an enemy civilization (Puppeteers)[1].

[1]https://en.wikipedia.org/wiki/Pierson%27s_Puppeteers