What type of bacteria cannot survive in the presence of oxygen?

The correct answer is indeed the type of bacteria known as obligate anaerobes. These microorganisms are characterized by their inability to survive in environments containing oxygen. They rely on anaerobic processes for their metabolic needs, meaning they engage in fermentation or anaerobic respiration. Oxygen is toxic to obligate anaerobes and can lead to damage or death, as they lack the necessary enzymes to neutralize reactive oxygen species.

Facultative anaerobes, on the other hand, can thrive in both aerobic and anaerobic environments, as they can switch their metabolic pathways depending on the availability of oxygen. Aerotolerant anaerobes can tolerate oxygen but do not use it for their metabolic processes, while microaerophilic bacteria require low levels of oxygen for growth but cannot be exposed to normal atmospheric levels. Understanding these classifications helps in microbiology and related fields, especially in recognizing how different bacteria behave in various environments.