Which of the following bacteria is known for its ability to form spores?

The ability of certain bacteria to form spores is a significant characteristic that allows them to survive in adverse environmental conditions, such as extreme temperatures, drought, and lack of nutrients. Clostridium and Bacillus are two genera that are well-known for their spore-forming capabilities.

Clostridium species, such as Clostridium botulinum and Clostridium tetani, can produce hardy spores that can withstand unfavorable conditions, allowing the bacteria to persist in environments where they might otherwise die. Similarly, Bacillus species, including Bacillus anthracis, the causative agent of anthrax, can form spores that are resistant to heat, desiccation, and disinfectants.

These spores serve as a survival mechanism, enabling the bacteria to remain dormant until conditions become favorable for growth. In contrast, the other bacterial groups listed do not typically exhibit spore formation, which is what distinguishes Clostridium and Bacillus in this context.