Extremophile microbes

The Berkeley Pit [an abandoned open pit mine] had become one of the deadliest places on earth, too toxic even for microorganisms. Or so it was thought.
In 1995, an analytic chemist named William Chatham saw something unusual in the allegedly lifeless lake: a small clump of green slime floating on the water's surface. He snagged a sample and brought it to biologist Grant Mitman at the nearby Montana Tech campus of the University of Montana, where Mitman found to his amazement that the goop was a mass of single-celled algae...
For reasons that are not entirely clear, many compounds which attack cancer cells are also harmful to brine shrimp, therefore most modern assay tests include the brine shrimp lethality test as a standard procedure. The Stierles exposed swarms of tiny crustacean volunteers to the Berkeley Pit chemicals, and to their delight, five of the chemicals showed anti-cancer properties.