How Bacteria Function

In response to limited nutrients or other harsh conditions, many [[KW]] Bacteria [[/KW]] survive by forming spores that resist the environmental stress. Spores preserve the bacterial [[KW]] DNA [[/KW]] and remain alive but inactive. When conditions improve, the spore germinates (starts growing) and the bacterium becomes active again.
The best-studied spores form within the bodies of Bacillus and Clostridium bacteria, and are known as endospores. Clostridium botulinum spores cause deadly botulism poisoning. Endospores have thick coverings and can resist environmental stress, especially heat. Even boiling in water does not readily kill them. But they can be killed by heating in a steel vessel filled with steam at high temperature and high pressure. Endospores can live for centuries in their dormant state.
Some bacteria form other types of spores. These spores are usually dormant but not as heat resistant or long-lived as endospores. Some aquatic bacteria, for example, attach to surfaces and produce swarmer [[KW]] cells [[/KW]] during division. The swarmer cell swims away to attach to another surface and give rise to still more swarmer cells. Still other bacteria survive by forming colonies made up of millions of cells that act in a coordinated way to keep the organism alive.