1. Archaebacteria are ancient group of bacteria living in extreme environments. 2. They are characterized by possessing cell walls without peptidoglycan. 3. The lipids in their plasma membrane are branched differing from all other organisms. 4. They are categorized into methanogens, halophiles and thermoacidophiles.
They are strict anaerobes.
They occur in marshy areas and convert formic acid and carbon dioxide into methane with the help of oxygen.
For example, Methanobacterium, Methanococcus.
They are aerobic chemoheterotrophs.
They occur in salt rich substrata like salt pans, salt beds and salt marshes.
For example, Halobacterium, Halococcus.
It is an archaebacteria that thrive in strongly acidic environments at high temperatures.