Some examples of aerobic bacteria include Mycobacterium tuberculosis, which causes tuberculosis, bacteria in the Nocardia genus, which cause nocardiosis, and Psuedomonas aeruginosa, which causes pneumonia, urinary tract infections and gastrointestinal issues. Wholly aerobic bacteria have oxygen-based metabolisms and cannot survive without oxygen.
Anaerobic bacteria do not require oxygen. The differences between anaerobic and aerobic bacteria can be seen when they are placed in a culture medium. The aerobic bacteria collect at the surface of the liquid medium so as to be exposed to the maximum amount of oxygen. Some bacteria can use, but do not need, oxygen; other types cannot survive in the presence of free oxygen at all.