Acidophiles are organisms that thrive in highly acidic environments, typically with a pH level below 3. These microorganisms can be found in places like acid mine drainage, hot springs, and even some types of soil. They have adapted to survive and grow in conditions that would be harmful or lethal to most other life forms. Many acidophiles are types of bacteria and archaea, which have specialized mechanisms to maintain their internal pH and protect their cellular structures. Some acidophiles, such as Thermoplasma and Ferroplasma, play important roles in biogeochemical cycles and can be used in biotechnological applications, including metal recovery and waste treatment.