Botulism bacteria, or Clostridium botulinum, grow in poorly preserved canned foods, especially meat and fish. The microbe's toxin could be lethal as a bioweapon. Dr. Phil Luton/Science Photo Library/Corbis hide caption

itoggle caption Dr. Phil Luton/Science Photo Library/Corbis

The botulism toxin comes from Clostridium botulinum bacteria, seen here in a colorized micrograph. James Cavallini/Science Source hide caption

itoggle caption James Cavallini/Science Source