Bacillus subtilis
Ellen Kirk

Bacillus subtilis is a Gram positive, rod shaped bacteria, commonly found in soil. It was originally named “Vibrio subtilis” when it was discovered in 1835 by Christian Gottfried Ehrenberg. It was renamed “Bacillus subtilis” in 1872 by Ferdinand Cohn. This bacterium is also known by the names hay bacillus, grass bacillus, or Bacillus globigii. Bacillus subtilis is an endospore forming bacteria, and the endospore that it forms allows it to withstand extreme temperatures as well as dry environments. Bacillus subtilis is considered and obligate aerobe, but can also function anaerobicly when in the presence of nitrates or glucose. Bacillus subtilis is not considered pathogenic or toxic and is not a disease causing agent. Bacillus subtilis has a flagellum which makes motility faster.

Since this bacterium is resistant to extreme temperatures, it can with stand high cooking temperatures. This is not to cause alarm, as it does not cause sickness if ingested. This bacterium can cause a stringy consistency in spoiled bread dough, if dough is exposed.

Bacillus subtilis is readily present everywhere; the air, soil and in plant compost. It is predicted that it spends most of it time inactive and in spore form. When the bacterium is active though, it produces many enzymes. One enzyme contributes to the plant degradation process. Bacillus subtilis can also be found in the human body, mostly on the skin or in the intestinal tract. However it is very rare for this bacterium to colonize on the human body.

Along with enzymes, Bacillus subtilis also produces a toxin called subtilisin. Subtilisin can cause allergic reactions if there is repeated exposure in high concentrations. This only poses a risk to fermentation plants that use high quantities of subtilisin. Exposure restrictions have been imposed by OSHA for the factory setting and can be found on their website (Occupational Safety & Health Administration). Subtilisin is also used in laundry detergent. It has been known to cause allergic reactions after using such detergent, however only in large quantities.

There are several uses for Bacillus subtilis and the enzymes it produces. It can be used to create proteases and amylase enzymes. At one point Bacillus subtilis was widely used as a broad spectrum antibiotic. This was lost after the ability to produce cheaper, large-scale antibiotics. It is still used in Western Europe and the Middle East in alternative medicine. Bacillus subtilis can convert dangerous explosives into just compounds of nitrogen, carbon dioxide and water (Wikipedia). The proton binding properties of the surface of this bacterium can also play a role in the degradation of radioactive waste (Wikipedia). Bacillus subtilis has also been used as a soil inoculant, and was at one time used in biological warfare tests run during the Cold War. Other commercial applications of Bacillus subtilis include cleaning agents in detergents, in de-haring and batting in the leather industry, in the production of special Japanese and Korean food, starch modification, the de-sizing of textiles, and other specialized chemicals. Bacillus subtilis also produces some fungicidal compounds, which are being investigated as control agents of fungal pathogens. It is currently being used as a fungicide for plant and ornamental seeds as well as various agricultural seeds.

Besides its many uses and applications, Bacillus subtilis has become the model agent in laboratory research because of its easy genetic manipulation. It has been applied to studies of E. coli, because they house many similarities.

Works Cited

European Bioinformatics Institute. “Bacteria Genomes – Bacillus Subtilis.” (2006-2009). <http://www.ebi.ac.uk/2can/genomes/bacteria/Bacillus_subtilis.html> (February 22, 2009).

Occupational Safety & Health Administration. “Chemical Sampling Information – Subtilisins.” (September 19, 2007). <http://www.osha.gov/dts/chemicalsampling/data/CH_268300.html>  (February 22, 2009).

U.S. Environmental Protection Agency. “Bacillus subtilis Final Risk Assessment.” (September 24, 2007). <http://www.epa.gov/biotech_rule/pubs/fra/fra009.htm> (February 22, 2009).

Wikipedia. “Bacillus subtilis.” (February 18, 2009). <http://en.wikipedia.org/wiki/Bacillus_subtilis> (February 22, 2009).  (information and picture).

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.

 

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