• The bacteria that cause botulism, Clostridium botulinum, can form endospores in canned food.canned fish image by Aleksandr Ugorenkov from Fotolia.com
  
  Endospores are dormant bacterial structures seen in only a handful of bacterial genera that help protect a bacterium's genetic material during suboptimal environmental conditions. They were first discovered by Ferdinand Cohn in 1876 and were given the name endospore because of their unique protein configuration. An endospore is made up of an outer layer, the exosporium, and a tough inner layer referred to as a spore coat. Endospores can be a threat to public health as they are often impervious to many sanitation techniques such as chemical disinfectants and ultraviolet radiation.
  
  

Bacillus

• Bacteria from the Bacillus genus are rod-shaped, aerobic and form endospores. A number of Bacillus bacteria are potentially harmful to human beings, such as Bacillus anthracis, which causes the disease known as anthrax. Many of them are particularly resistant to harsh chemical and physical conditions.
  
  

Clostridium

• Bacteria of the Clostridium genus are rod-shaped, anaerobic and are all capable of forming endospores. Most of them are harmless; however, a few of them are life-threatening pathogens. For example, the Clostridium bacterium C. tetani causes the nervous system infection known as tetanus, and the bacterium C. perfringens can cause gas gangrene in wounds.
  
  

Paenibacillus

• Paenibacillus bacteria are aerobic, gram positive and are commonly found in the environment (i.e., soil and plant tissues). They have been shown to strengthen a plant's resistance to disease and can also contribute to plant growth.