The Archaebacteria are the most primitive bacteria that defines the limits of life.
Members of this archaea include the bacteria that can survive in the temperature range of 113 °C and found living in hydrothermal vent.
Example: Pyrolobus fumarii
Some of the Archaebacteria were found in the most acidic conditions (soil) that were known to grown at the pH of 0 and were known as methanogens.
These bacteria were capable of producing methane gas in hot spring and marshes, et cetera.
