extremophile

ekstremofiili puhekieltä An organism that lives under extreme conditions of temperature, salinity etc; commercially important as a source of enzymes that operate under similar conditions.
2003, (w), A Short History of Nearly Everything, BCA, p. 207:

They had found the world's first extremophiles – organisms that could live in water that had previously been assumed to be much too hot or acid or choked with sulphur to bear life.