1. Two sub-types exist : facultative anaerobe and obligate anaerobe . 2. Comparing to them, obligate anaerobes can be harmed by oxygen. 3. Halanaerobiales are halophilic obligate anaerobes with a fermentative or homoacetogenic metabolism. 4. They are obligate anaerobes and oxygen is toxic to them. 5. However, microaerophiles metabolise energy aerobically, and obligate anaerobes metabolise energy anaerobically. 6. It is an obligate anaerobe , meaning that oxygen is poisonous to the cells. 7. This species is an obligate anaerobe and is found in the rumen of cows. 8. An important distinction needs to be made here between the obligate anaerobes and the microaerophiles. 9. Microaerophiles, like the obligate anaerobes , are damaged by normal atmospheric concentrations of oxygen. 10. Obligate anaerobes exist simply because they lost the ability over the course of evolution to operate without oxygen.
