Aquifex is a genus of bacteria that thrive in extremely hot environments, such as hot springs and hydrothermal vents. These microorganisms are classified as thermophiles, meaning they prefer high temperatures, often exceeding 70 degrees Celsius (158 degrees Fahrenheit). They play a crucial role in the ecosystem by participating in the cycling of nutrients in these extreme habitats. These bacteria are notable for their unique metabolic processes, which allow them to utilize hydrogen and sulfur compounds for energy. Aquifex species are also of interest to scientists studying the origins of life on Earth and the potential for life on other planets, such as Mars or the moons of Jupiter.