A facultative anaerobe can do what?

A facultative anaerobe is a type of organism that has the ability to grow in both the presence and absence of oxygen. This versatility allows facultative anaerobes to switch between aerobic respiration, which uses oxygen to generate energy, and anaerobic fermentation, which does not require oxygen but produces energy through different biochemical pathways. This adaptability is advantageous in various environmental conditions, where the availability of oxygen can fluctuate.

In contrast, organisms that only grow with plenty of oxygen are classified as obligate aerobes, while those that grow only without oxygen are termed obligate anaerobes. The term "facultative" indicates that these organisms can adjust their metabolic processes based on the oxygen availability, making them uniquely capable of thriving in diverse environments.