Spores of which bacterium are considered the most heat resistant?

The spores of Bacillus subtilis are regarded as the most heat resistant among the options provided. Bacillus subtilis is a well-studied bacterium known for its ability to produce endospores, which are a dormant and highly resilient form of the bacterium that can withstand extreme conditions, including high temperatures. The sporulation process allows the bacterium to survive in harsh environments that would be lethal to the vegetative form.

Endospores are capable of withstanding heat, desiccation, radiation, and various chemical agents, making them particularly challenging to eliminate in food processing and safety contexts. This characteristic is important for sanitarians and those involved in public health, as it highlights the potential risk these spores pose in food safety and the need for appropriate cooking and sterilization methods to eliminate them.

In comparison, other bacteria listed have different survival strategies and heat resistance levels. For example, Clostridium perfringens and Clostridium botulinum also produce spores, but their resistance is generally lower than that of Bacillus subtilis. Escherichia coli, while it may produce biofilms and can be pathogenic, does not form spores at all, making it significantly less heat resistant than spore-forming bacteria