Spore-forming bacteria

Rieu-Lesme F, Dauga C, Morvan B, et al. 1996. Acetogenic coccoid spore-forming bacteria isolated from the rumen. Res Microbiol 147 753-64. 

The most frequently utilized to challenge moist heat sterilization cycles are Bacillus stearothermophilus and Clostridium sporogenes, spore-forming bacteria are selected because of their relatively high heat resistance. In addition to the selection of an appropriate organism for use as a biological indicator, the concentration and resistance of the indigenous microbial population is established. 

Spore Formation Some bacteria form spores when growth ceases due to starvation or other causes. Spores are more resistant than normal cells to heat, drying, radiation, and chemicals. Spores can remain alive for many years however, they can convert back to normal cells at proper conditions. Spore-forming bacteria are found most commonly in the soil. 

Under nnfavorable conditions, some species of bacteria, mostly bacillus such as the Bacillus and Clostridium, assnme a form within the cytoplasm that is resistant to environmental inflnences adverse to bacterial existence. This form is called spores. The cocci and spirilla rarely exhibit this behavior—this form being confined only to abont 150 species of the bacilli. The most important pathogenic, spore-forming bacteria are those cansing tetanns, gas gangrene, botnlism, and anthrax. 

Clostridia are spore forming bacteria. Their spores are more resistant and higher temperatures for a longer time must be used for inactivation (autoclave for 1 h at 130°C). Refer to an appropriate laboratory safety book, and see also Chapter 20. 

In most situations, rapid resumption of operations will depend on effective decontamination of installations, personnel, and equipment. This is especially true for persistent chemical agents and spore-forming bacteria and some viruses. 

Vegetative Cells are non spore-forming bacteria or spore-forming bacteria in their non-sporing state. 

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