What type of bacteria can become dormant by slowing its metabolism?

The correct answer refers to Gram-positive bacilli, specifically certain species such as those in the Bacillus genus. These bacteria have the ability to form endospores, allowing them to enter a dormant state when environmental conditions become unfavorable. During this dormant state, the bacteria slow down their metabolism significantly, which enables them to survive extreme conditions like heat, desiccation, and nutrient deprivation.

In contrast, other types of bacteria listed may not exhibit the same dormancy characteristics. Gram-negative cocci, for instance, do not typically form endospores and are more susceptible to environmental stress. Mycobacteria, while they have unique survival mechanisms, do not form endospores as Gram-positive bacilli do; instead, they have a waxy cell wall that helps them resist certain harsh conditions. Spirilla, which are spiral-shaped bacteria, also do not share the same dormancy features as endospore-forming Gram-positive bacilli.

Understanding the ability of Gram-positive bacilli to enter a dormant state is crucial in microbiology, especially in sterilization and infection control practices, as these endospores can withstand disinfection processes and may lead to potential outbreaks if not properly managed.