What are some examples of bacteria that can form an endospore? How long is it generally viable?

Examples of bacteria that can form endospores include Bacillus anthracis (causing anthrax) and Clostridium tetani (causing tetanus). Endospores are highly resistant and can remain viable for years, even centuries, in harsh environmental conditions. They can survive extreme heat, radiation, and chemical treatments, making them extremely difficult to destroy.