The remnants of the mother cell dissolve away leaving the spore. The proteins are also resistant to breakage. Finally, this tough membrane is coated on the outer surface by proteins. The thick peptidoglycan makes the double membrane layer very tough and hard to break apart. Peptidoglycan is normally present in the bacterial cell wall, but not in nearly the same amount. Between these two membranes a think layer of a rigid material forms. This creates a daughter cell that is surrounded by two layers of membrane. In the next stage of spore formation, the membrane that surrounds the mother cell surrounds the daughter cell. The remainder of the bacterium is called the mother cell. This smaller cell is called a daughter cell. This isolates one of the copies of the genetic material from the remainder of the bacterium. Then, the membrane coat that surrounds the inside of the bacterium pinches inward until the ends of the inward growing membrane meet. The genetic material of the bacterium is duplicated. After monitoring the environment for a period of time, the deteriorating conditions trigger the microbe to begin the change from a growing and dividing cell to a dormant spore. Bacteria are equipped with a whole battery of sensing proteins and other compounds that monitor environmental conditions of temperature, pH of the surrounding fluid, water content, and availability of food, as some examples. The process begins when a bacterium senses that the environmental conditions are becoming life threatening. The multistep process of forming a spore is known as sporulation. Other microorganisms of human concern that form spores include protozoa (e.g., Microsporidia ) and fungi (e.g., Actinomycetes).įormation of bacterial spores. The spores would survive to cause illness. Because the spores are hardy and can be transported virtually undetected, they could be taken to food plants or supermarkets, where the food could be contaminated.

The contamination of foods by terrorists is a significant security concern, especially in the United States. When the food is eaten, the dormant bacteria begin to grow again and produce a variety of potent toxins that disrupt the nervous system, causing serious illness. This bacterium can also survive in canned foods for extended time periods, even when the food has been heated or is acidic. The bacterium and the spore are widespread in nature for example, they are a common inhabitant of the soil. Anthrax spores were used as a mechanism of bioterrorism to target United States citizens by deliberate dispersal in the mail system in late 2001.Īnother prominent example of a bacterial spore former of concern is Clostridium botulinum. The resulting lung infection, which is called inhalation anthrax, is almost always fatal without prompt medical treatment. As a result, they can be readily dispersed through the air and can be easily inhaled into the lungs. Bacillus anthracis, the bacterium that causes anthrax, is a spore former. Spores are noteworthy in terms of security because of the threat they pose in the hands of terrorists. Anthrax spores that could germinate into living bacteria were recovered on Gruinard Island, an island off the coast of Scotland that was used for biological weapons testing by the British government during World War II. Thus, spores offer an extraordinary form of protection to bacteria.

Spores of bacteria that subsequently could be revived into the growing form have been recovered from materials that are over a century old. In contrast, spores can survive exposure to 120 ☌ for several hours. A group of bacteria known as thermophilic bacteria can survive these temperatures, but temperatures of 120 ☌ (248 ☏) kill even thermophiles. These high temperatures cause structural components of the bacteria to dissolve, and strands of genetic material to separate from one another. Temperatures of 80 to 90 ° Celsius (176 –194 ☏) typically kill bacteria that are growing and dividing within minutes. The effect of temperature on bacterial and spore survival provides a good example of the resilience of bacterial spores. When the environmental conditions are so harsh that the growing form of the microbe would be killed. This physically and chemically resilient package protects the genetic material during periods A spore is a hard casing that contains the genetic material of those bacteria and other microorganisms that are able to form the structure.

Spore formation