Which type of bacteria can survive in both the presence and absence of oxygen?

Facultative anaerobes are the type of bacteria that can thrive in both the presence and absence of oxygen. This versatility allows them to switch their metabolism based on the availability of oxygen in their environment. When oxygen is present, facultative anaerobes typically utilize aerobic respiration to generate energy, which is more efficient. However, in the absence of oxygen, they can shift to anaerobic respiration or fermentation to continue producing energy, although this process is less efficient than aerobic respiration.

This adaptability is crucial for survival in various environments, as it enables these bacteria to colonize and thrive in diverse habitats where oxygen levels may fluctuate. The other types of bacteria mentioned have specific oxygen requirements that do not allow for this flexibility, making facultative anaerobes uniquely capable of surviving in different conditions.