Texas Wastewater Class B Practice Exam

Which type of bacteria cannot survive with oxygen present in the water?

1. Aerobic bacteria

2. Facultative bacteria

3. Anaerobic bacteria

4. Coliform bacteria

The correct answer is: Anaerobic bacteria

The correct answer is the type of bacteria that cannot survive in the presence of oxygen, which are known as anaerobic bacteria. These microorganisms thrive in environments devoid of oxygen and rely on alternative metabolic processes to derive energy. In wastewater treatment systems and similar environments, anaerobic bacteria play a crucial role, particularly in processes such as anaerobic digestion, where organic matter is broken down in the absence of oxygen, leading to the production of biogas. Aerobic bacteria, in contrast, require oxygen for growth and function effectively in oxygen-rich environments. Facultative bacteria are versatile and can switch between aerobic and anaerobic processes depending on the availability of oxygen. Coliform bacteria serve as indicators of water quality and can exist in both aerobic and anaerobic conditions. Therefore, anaerobic bacteria's inability to survive in an oxygenated environment is what distinguishes them from these other types.