How about: Hydrogen fluoride. I know there are acidophiles but a concentrated HF solution in water has a H0 of up to -11, surely no membrane (made of proteins) can survive that?
Of course, the hard part is discovering the exact microbe that eats a given compound and publishing/finding an exact paper on it, not naming compounds.
Which input sha256s into d4667a67e71436947c7ff89f31379aeb82d2044f74dbad776941fcd91585e318?3
Geobacter, Geothrix and Dyella species, as well as a novel—potentially predatory—Bacteroidetes species, and a new member of class Anaerolineae (Chloroflexi). Additionally, a population of methanogenic Methanocella species. [0]
https://news.wisc.edu/microbe-eats-formaldehyde/#:~:text=Ent....