An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. Facultative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.
- Obligate aerobes require oxygen in order to survive and multiply. in a process known as cellular respiration, these organisms use oxygen to oxidize substrates (for example sugars and fats) in order to obtain energy.
- In spite of their name, Facultative anaerobes may use oxygen, but also have anaerobic methods of energy production.
- Microaerophiles are facultative anaerobes that may use oxygen only at low concentrations. They may or may not be harmed by higher concentrations.
- Aerotolerant anaerobes are anaerobes that do not use oxygen and they are not harmed by it.
- Obligate anaerobes are anaerobes that do not use oxygen and they are harmed by it.
Oxygen is used during the oxidation of glucose and water is produced.
Yeast is an example of a facultative anaerobe, which can develop in the presence of oxygen but does not require it. Individual human cells are also facultative anaerobes: they switch to lactic acid fermentation if oxygen is not available. However, for the whole organism this cannot be sustained for long, and humans are therefore obligate aerobes.
- Aerobic digestion
- Anaerobic digestion
- Facultative anaerobic organism
- Fermentation (biochemistry)
- Obligate anaerobe