Though many bacteria thrive in high heat, none are able to live in lava due to the extremely high temperature. The common misconception that bacteria live in lava comes from the discovery of archaeabacteria, which were formally classified as a bacteria. Heat-resistant bacteria have been discovered as well, and both bacteria and archaebacteria can live off the carbon components of lava that has cooled.
Bacteria and archaeabacteria that can survive extreme heat are scientifically known as thermophiles. The heat-resistant bacteria named Thermus aquaticus was discovered in the hot springs of Yellowstone National Park. This bacteria is able to withstand temperatures as high as 175 degrees Fahrenheit. Later, it was discovered that both bacteria and archaeabacteria lived near hydrothermal vents at around 380 degrees Fahrenheit.
Bacteria have not been recorded to survive higher temperatures than those found at the hydrothermal vents. While thermophiles may easily thrive in extremely harsh environments, such as near sea vents and hot springs or in the boiling mud surrounding a volcano, lava has a temperature between 1,200 and 2,000 degrees Fahrenheit, so it seems unimaginable that a bacteria or archaeabacteria could survive in such conditions. If this is a possibility, it has yet to be proven.