👉 Thermococcus is a single-cell bacterium found in marine environments, primarily in cold water. It is characterized by its ability to survive under extremely low temperatures, which can range from -40°C (-28°F) or below to as low as -15°C (-9.6°F). Thermococcus has the ability to grow on a wide variety of substrates such as ice, ice crystals, and even sand grains, making it an important source for biological research.