Bacillus clausii characteristics, morphology and benefits

Abraham McLaughlin

Bacillus clausii it is one of the many bacterial species that belong to the genus bacillus. It is located within the most innocuous bacteria, since they do not have pathogenic effects on man. It is also part of the intestinal bacterial flora. It belongs to the group of microorganisms that maintain symbiotic relationships with their host.

Likewise, it is a sporulated bacterium, which has been the subject of numerous studies for its properties and applications for the benefit of human health. Spores of Bacillus clausii are the active principle of the drug Enterogermina, which is frequently used in the treatment of diarrhea caused by alteration of the intestinal microbiota.

Bacillus clausii isolated from the drug Enterogermina. Source: By Giraffe Gregor [GFDL ( or CC BY-SA 4.0 (], via Wikimedia Commons

Thanks to the health benefits of the Bacillus clausii, it has been included among the so-called probiotics ("pro-life"), which are live, non-pathogenic microorganisms that are administered in adequate doses. Once inside the body, they exert a positive influence on the health and physiological balance of the host..

Article index

  • 1 Taxonomy
  • 2 Morphology
  • 3 General characteristics
    • 3.1 Gram positive
    • 3.2 Aerobic
    • 3.3 Metabolism
    • 3.4 Growth
    • 3.5 Habitat
    • 3.6 Resistance to antibiotics
  • 4 Benefits for humans
    • 4.1 Probiotics
    • 4.2 Treatment of diarrhea
    • 4.3 Effects on the gastrointestinal tract
    • 4.4 Production of substances
    • 4.5 Adherence to the intestinal wall
    • 4.6 Regulates immune activity
    • 4.7 Vitamins production
  • 5 References


The taxonomic classification of an organism is important because it allows determining the characteristics that a living being can have, as well as the behavior it can have under certain environmental conditions..

The taxonomic classification of the Bacillus clausii it is:

Domain: Bacteria

Edge: Firmicutes

Class: Bacilli

Order: Bacillales

Family: Bacillaceae

Gender: Bacillus

Species: Bacillus clausii


As the name implies, the Bacillus clausii It is a rod-shaped bacterium with rounded edges. Under the microscope, several bacterial cells are observed together, forming long chains. The cell is surrounded by a fairly thick cell wall.

Similarly, it has flagella on the entire surface of the cell. It measures 2-3 microns long by 1 micron wide. Circular colonies can be seen in agar cultures, which may be 3 - 4 mm in diameter..

From a genetic point of view, Bacillus clausii has a single circular chromosome. In it, 4204 genes are contained, of which 4096 code for the expression of certain proteins.

As it is a sporulated organism, inside the bacterial cell the spore can be observed, which does not cause a modification in the conventional form of the bacterium.

General characteristics

Gram positive

Bacillus clausii belongs to the group of gram-positive bacteria. This means that it has a peptidoglycan in its cell wall that traps Gram's stain particles, causing the cell to be stained purple..


In the same way it is a strict aerobic bacteria. It must be in environments with oxygen availability to carry out its metabolic processes.


With regard to metabolism, the bacterium is capable of using various carbon sources, such as galactose, dulcitol, sorbitol and L-aribose. In the same way, it is capable of reducing nitrates to nitrites in processes to obtain energy..


For its growth it requires an approximate temperature of 40 ° C and an alkaline environment, with an optimum pH of 9.0.

It is also capable of decomposing hydrogen peroxide into water and oxygen, thanks to the presence of the enzyme catalase..


Regarding the habitat, it is mainly found in alkaline environments. Its spores are quite resistant, being able to survive even the action of bile salts, as well as high temperatures of up to 100 ° C.

Antibiotic resistance

This bacterium has shown high levels of resistance to antibiotics such as cephalosporin, erythromycin, lincomycin, and cycloserine. However, contrary to what might be thought, this does not condition its pathogenicity, since it does not cause any type of pathology in humans..

Benefits for the human being

The Bacillus clausii It is a bacterium that reports certain benefits for humans and so far, no harm.


It is included in the wide group of probiotic microorganisms, which are ingested and contribute to solving certain pathological conditions. In the case of Bacillus clausii, has been used in various ways.

Treatment of diarrhea

It has been shown to be useful in the treatment of diarrhea caused by the ingestion of antibiotics, in certain respiratory conditions and in the prevention of some diseases such as diverticulitis.

Spores of Bacillus clausii they are often chosen as treatment. This is because they are very resistant and can travel through the upper gastrointestinal tract to the colon. All this without being affected by the levels of acidity that exist, for example in the stomach.

Effects on the gastrointestinal tract

The beneficial effects of this bacterium on the gastrointestinal tract are varied. First, it has been shown to synthesize and release antimicrobial substances that are capable of killing various types of pathogens..

Substance production

Particularly valuable is the production of active substances that act against other bacteria, specifically the Staphylococcus aureus, Enterococcus faecium Y Clostridium difficile.

Adherence to the intestinal wall

Likewise, another of the mechanisms of action that this bacterium has at the gastrointestinal level is that its spores adhere to the wall of the intestine, colonizing it, thus preventing other pathogenic microorganisms from doing so..

Regulates immune activity

Another beneficial effect is that they regulate immune activity, stimulating the production of a type of antibody known as Immunoglobulin A. This antibody plays a very important role in the defense of the body against bacterial and viral agents..

Immunoglobulin A prevents bacteria and viruses from adhering to intestinal epithelial cells and thus causing tissue damage.

Vitamins production

Likewise, according to certain studies, the Bacillus clausii It can produce certain vitamins, including some of the B complex. Thanks to this, it could also be used to treat vitamin deficiencies. However, this is a point on which multiple investigations are still being carried out..

Taking into account the aforementioned benefits, medicines containing spores of Bacillus clausii. Among these, one of the most recognized is Enterogermina.

The Bacillus clausii It is a bacterial specimen that has generated great benefits in the field of human health. However, all have not yet been elucidated. The action at the gastrointestinal level is widely known, but in other areas, such as the respiratory tract, many questions remain to be answered..

This is a complex bacterium, the properties of which arouse the interest of scientists. That is why every day there are more studies that are carried out to establish reliably its role in the recovery and maintenance of health in humans..


  1. Bacillus clausii. Retrieved from
  2. Curran, R. Immunoglobulin A (IgA). Obtained from:
  3. Duc, L., Hong, H., Barbosa, T., Henriques, A. and Cutting, S. (2004, April). Characterization of Bacillus Probiotics available for Human Use. Applied and Enviromental Microbiology. 70 (4). 2161 - 2171.
  4. González, J. (2015, March). Prevention of Recurrent Acute Diverticulitis with Bacillus clausii. Journal of the Venezuelan Society of Gastroenterology. 69 (1). 2-6
  5. León, K., Urbina, H., Sánchez, E., Abraham, A. and Artis, M. (2015, December). Products and Effects. Venezuelan Archives of Childcare and Pediatrics. 78 (4).
  6. Marseglia, G., Tosca, M., Cirillo, I., Licari, A., Leone, M., Marseglia, A., Castellazzi, A. and Ciprandi, G. (2007, March). Efficacy of Bacillus clausii spores in the prevention of recurrent respiratory infections in children: a pilot study. Therapeutics and Clinical Risk Management. 3 (1). 13 - 17
  7. Neelamraju, J. and Ratna, M. (2015, January). Bacillus clausii - The Probiotic of Choice in the Treatment of Diarrhoea. Yoga & Physical Therapy. 5 (4).
  8. Urdaci, M. and Pinchuk, I. (2004, January). Chapter 15: Antimicrobial Activity of Bacillus Probiotics. Retrieved from:

Yet No Comments