Ahh, the human experience of hyperbolically overstating everything! How wonderous! But, realistically, this isn't that new. Microbes can adapt to most anything, we've found. Like creating organisms that fee off the of the heat and chemical toxicity of a sulfur vent on the ocean's floor, or certain plants substituting red chlorophyll for green, utilizing a different part of the light spectrum for energy. Life wants to survive, and it will do so no matter what nature throws it, for as long as it can. Things adapt, evolve, and change, and for things without a will, they sure do seem to do whatever they can to survive.
Though, on the other hand...an arsenic based lifeform would be something that we would take issue with eating...
Though, on the other hand...an arsenic based lifeform would be something that we would take issue with eating...