Matt Brown, Genie Song - B. pumilus

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Template:B. ''pumilus''


  • Kingdom: Bacteria
  • Phylum: Firmicutes
  • Class: Bacilli
  • Order: Bacillales
  • Family: Bacillaceae


NCBI: Taxonomy

  • Genus: Bacillus
  • Species: pumilus

Habitat Information

The soil sample was collected from 6607 Brodie Lane, Austin TX, 78745. January 24th with no rainfall in the previous 24 hours, no solar radiation, 46% humidity, 30.44 inches of seal level pressure and an air temperature of 65 degrees Fahrenheit. The soil consisted of a speck stony clay loam.

Description and Significance

  • Colonial morphology: Irregular, wrinkled and opaque. Colonies are smooth with a yellow tint. Margins are undulated.
  • Cellular morphology: Rod shaped, bacillus, gram positive, and motile.
  • Significance:Shows high resistance to environmental stresses such as: UV radiation, hydrogen peroxide, and desiccation (state of extreme dryness).
    Isolates of B. pumilus were recently recovered aboard the International Space Station from hardware surfaces and air particles.
    Food intoxications to humans and may produce toxins.
    Its plasmids used for gene transfer systems.
    Involved in rectal fistulas.
    Causes widespread lysis and damage to HEp-2 cells.
    Used in agriculture for its antifungal activity as fungicides. Growth of the bacterium on plant roots prevents Rhizoctonia and Fusarium spores from germinating.
    Generally non-pathogenic, only three documented cases of cutaneous infection and two septic infections.

Genome Structure

B. "pumilus" is created from a singular circular chromosome of an estimated 4000 genes and a median protein count of 3721. The most common bases being GC compromising 41.5% of the sequence. The median length of the sequence is 3.7 Mb.



Cell Structure, Metabolism and Life Cycle

  • The cellular structure is similar to other Bacillus species. It creates endospores and contains a single circular chromosome. It is a gram positive structure therefore has a cell wall composed of a thick peptidoglycan layer. It is a motile organism and is an aerobe (requires oxygen for respiration). It can ferment sucrose and glucose but not lactose. B. pumilus lacks several DNA repair and oxidative stress response genes found in B. subtilis and B. licheniformis.
  • Life cycle of B. pumilus is similar to spore forming Bacillus species. There are three processes of the life cycle: 1. Vegetative growth 2. Sporulation 3. Germination. The development of the life cycle to the next depends on nutrient availability. Cannot grow anaerobically, cannot hydrolyze starch, and cannot reduce nitrate.

Physiology and Pathogenesis

  • Gram Reaction: Gram positive
  • Capsule stain: Negative
  • Endospore stain: Positive
  • Motility results: Motile
  • Phenol Red Broth: No change
  • Starch Hydrolysis: No clearing
  • Casein Hydrolysis: No clearing. Casease is absent. Negative.
  • Gelatin Hydrolysis: Gelatin is solid. No gelatinase is present.
  • DNA Hydrolysis: Clearing in agar around growth. DNAse is present.
  • Lipid Hydrolysis: No clearing in agar. Lipase is not present.
  • Methyl Red: Negative.No color change. No mixed acid fermentation.
  • Voges Proskauer: Negative.
  • Citrate Test: Negative.
  • SIM Tests (3 in 1): Negative
  • Nitrate Reduction Test: Positive for nitrite.
  • Urea Hydrolysis: Negative
  • Triple Sugar Iron Agar: Negative, sulfur was used as terminal electron acceptor, no gas present.
  • PCR: Procedure performed in class
  • Oxidase: Negative.
  • Eosin Methylene Blue Agar: Negative (light pink).
  • Hektoen Enteric Agar: No change visible.
  • MacConkey Agar: Positive, no bile precipitate.
  • Decarboxylation: Lysine: negative; Ornithine and Arginine: positive.
  • Phenylalanine Deaminase: Negative.
  • Catalase: Positive.
  • Blood Agar: Alpha, partial clearing (green).
  • Mannitol Salt Agar: No change.
  • 6.5% NaCl Broth Salt Tolerance Test: Negative.
  • Bile Esculin Test: Negative.


  • Tena, D., Martinez-Torres, J., Perez-Pomata, M., Saez-Nieto, J., Rubio, V., and Bisquert, J. “Cutaneous infection due to Bacillus pumilus: Report of 3 cases”. Clinical Infectious Diseases. 2007. Volume 44. P. e40-2.
  • Prokaryotae, Regnum. “B. Pumilus.” ABIS Encyclopedia, 2012,
  • Atlas, Genome. “Bacillus Pumilus SAFR-032.” BacMap, Apr. 2017,
  • NIH. “Bacillus Pumilus (ID 440).” Advances in Pediatrics., U.S. National Library of Medicine, Apr. 2017,
  • Kimouli, Maria, et al. “Two Cases of Severe Sepsis Caused by Bacillus Pumilus in Neonatal Infants.” Journal of Medical Microbiology, Microbiology Society, 1 Apr. 2012,


Page authored by Matthew Brown and Eugenie Song, student of Prof. Kristine Hollingsworth at Austin Community College.