• First known as Vibrio subtilis, this bacterium was discovered by Christian Gottfried Ehrenberg in 1835. It was renamed in 1872 by Ferdinand Cohn.
• Bacillus subtilis (B. subtilis) is a Gram-positive, aerobic bacterium. It is rod-shaped and catalase-positive.
• B. subtilis is found in soil and the gastrointestinal tract of ruminants and humans.
• B. subtilis is considered the best studied Gram-positive bacterium and a model organism in the study of bacterial chromosome replication and cell differentiation.
• It is also known as hay bacillus, grass bacillus or Bacillus globigii.
• The word bacillus refers to the shape of the bacteria (rod-shaped) and subtilis means slim, slender.
• B. subtilis is often used as a probiotic preparation in the treatment or prevention of intestinal disorders. It is also used to produce antibiotics, as a fungicide, and in alternative medicine.
• This bacterium is part of the same family as Bacillus anthracis (anthrax).
• When stressed, B. subtilis transforms itself into a spore and enters a dormant state, allowing it to tolerate extreme environmental conditions.
• B. subtilis holds the record for surviving in space for the longest duration, 6 years on a NASA satellite.
• B. subtilis is generally considered non-pathogenic
• It has been implicated in food poisoning caused by poor quality bakery products among others.
• B. subtilis food poisoning has a rapid onset and with acute vomiting, commonly follow by diarrhoea.
• B. subtilis spores can survive the heat applied during cooking.
In the Lab / at Wickham Micro Ltd
• B. subtilis is one of the gallery of microorganisms used in the Quality Control of media for Microbiological Quality testing.
• B. subtilis is one of the many microorganisms used in method suitability and validation testing in compliance with Ph Eur 9.0 2.6.12, USP 40 <61> & JP XVII 4.05
• B. subtilis is a common source of environmental contamination in the laboratory and is routinely found on environmental settle plates and in active air monitoring. This is due to the ubiquitous nature of the microorganism in the environment.
• B. subtilis is often used as a safer substitute for other pathogenic varieties of Bacillus to determine the likely effects on Bacillus species and/or spore-forming microorganisms in general.
• It has an optimum growth temperature in the range of 30-39°C.
• Certain strains of subtilis can be used in biological indicators, predominantly to determine effectiveness of low temperature steam sterilisation processes. This could be for example if sterilising heat sensitive products. At WLL we would normally perform counts and identity tests on these biological indicators to confirm the information on the manufacturer’s certificate (ISO 11138).