Obligate aerobes are organisms that require oxygen to survive and grow. They use oxygen for cellular respiration, a process that generates energy by breaking down nutrients. Without oxygen, obligate aerobes cannot produce enough energy and will die. These organisms are commonly found in environments where oxygen is abundant, such as in soil and water. Examples of obligate aerobes include certain bacteria, like Mycobacterium tuberculosis, and many fungi. Their dependence on oxygen distinguishes them from other types of organisms, such as facultative anaerobes, which can survive with or without oxygen.