What term describes bacteria that can grow without oxygen?

The term that describes bacteria that can grow without oxygen is "obligate anaerobes." These microorganisms thrive in environments devoid of oxygen and are often inhibited or even killed by its presence. Obligate anaerobes obtain energy through fermentation or anaerobic respiration, using substrates other than oxygen as electron acceptors. They are adapted to survive and grow in specific niches, like deep-sea hydrothermal vents, the intestines of animals, and in environments where organic material is decomposed without oxygen.

In contrast, aerobes require oxygen for their metabolic processes; facultative anaerobes can utilize oxygen when it is available but can also grow without it. Microaerophiles require reduced oxygen levels for growth, meaning they don’t thrive in pure oxygen but do need some oxygen to survive. Understanding these different classifications helps clarify how bacteria adapt to various environmental conditions regarding oxygen availability.