Final answer:
Obligate anaerobes lack enzymes like superoxide dismutase and are harmed by oxygen, while facultative anaerobes and aerotolerant anaerobes have mechanisms to protect against oxidative stress.
Step-by-step explanation:
The statement that obligate anaerobes have enzymes such as superoxide dismutase to protect them from the damaging effects of oxygen is incorrect. In fact, obligate anaerobes usually lack protective enzymes like superoxide dismutase, peroxidase, and catalase, which neutralizes reactive oxygen species (ROS). These organisms use alternative electron acceptors and are typically harmed by the presence of oxygen. On the contrary, aerotolerant anaerobes do possess superoxide dismutase but not catalase, and facultative anaerobes have the whole range of enzymes needed to mitigate oxidative stress, making them capable of surviving in both aerobic and anaerobic environments.
Superoxide dismutases (SOD) are metalloenzymes found in many organisms, including plants, that protect against superoxide radicals by converting these highly reactive molecules to hydrogen peroxide and oxygen. Up-regulation of SOD is critical in defending against pathogens during a plant defense response. In the context of human pathogens, obligate aerobes like Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), require oxygen for survival and use it as a terminal electron acceptor in aerobic respiration.