What type of bacteria can grow in both aerobic and anaerobic conditions?

Facultative anaerobes are a unique group of bacteria capable of thriving in both the presence and absence of oxygen. These microorganisms have the metabolic flexibility to utilize oxygen when it is available for aerobic respiration, which yields more energy. However, they can also switch to fermentation or anaerobic respiration when oxygen is not present, allowing them to survive and grow in diverse environments.

In contrast, obligate aerobes require oxygen to survive, making them dependent on aerobic conditions. Obligate anaerobes are the opposite; they cannot tolerate oxygen and only grow under anaerobic conditions. Microaerophiles require a low concentration of oxygen for growth and can be inhibited by higher oxygen levels. Thus, facultative anaerobes stand out for their ability to adapt to varying oxygen conditions, making them more versatile in different environments.