Bacillus stearothermophilus

Bacillus stearothermophilus

Geobacillus stearothermophilus
Scientific classification
Kingdom: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Bacillaceae
Genus: Geobacillus
Species: G. stearothermophilus
Binomial name
Geobacillus stearothermophilus

Geobacillus stearothermophilus (formally Bacillus stearothermophilus)[1][2] is a rod-shaped, incubated. A color and/or turbidity change indicates the results of the sterilization process; no change indicates that the sterilization conditions were achieved, otherwise the growth of the spores indicates that the sterilization process has not been met.

Biological indicators are used in conjunction with chemical indicators and process indicators to validate sterilization processes.

It was first described in 1920 as Bacillus stearothermophilus,[3] but, together with Bacillus thermoglucosidasius, it was reclassified as a member of the genus Geobacillus in 2001.[4]


Recently, a DNA polymerase derived from these bacteria, Bst polymerase, has become important in molecular biology applications.

Bst polymerase has a helicase-like activity, making it able to unwind DNA strands. Its optimum functional temperature is between 60 and 65°C and it is denatured at temperatures above 70°C. These features make it useful in loop-mediated isothermal amplification (LAMP).[5] LAMP is similar to the polymerase chain reaction (PCR) but does not require the high temperature (96°C) step required to denature DNA.


  1. ^ Coorevits, A; Dinsdale, AE; Halket, G; Lebbe, L; De Vos, P; Van Landschoot, A; Logan, NA (July 2012). "Taxonomic revision of the genus Geobacillus: emendation of Geobacillus, G. stearothermophilus, G. jurassicus, G. toebii, G. thermodenitrificans and G. thermoglucosidans (nom. corrig., formerly 'thermoglucosidasius'); transfer of Bacillus thermantarcticus to the genus as G. thermantarcticus comb. nov.; proposal of Caldibacillus debilis gen. nov., comb. nov.; transfer of G. tepidamans to Anoxybacillus as A. tepidamans comb. nov.; and proposal of Anoxybacillus caldiproteolyticus sp. nov.". International journal of systematic and evolutionary microbiology 62 (Pt 7): 1470–85.  
  2. ^ "Notification that new names and new combinations have appeared in volume 50, part 2, of the IJSEM". International Journal of Systematic and Evolutionary Microbiology 51 (3): 795–6. 2001.  
  3. ^ DONK (P.J.): A highly resistant thermophilic organism" Journal of Bacteriology 1920, 5, 373-374.
  4. ^ T. N. Nazina, T. P. Tourova, A. B. Poltaraus, E. V. Novikova, A. A. Grigoryan, A. E. Ivanova, A. M. Lysenko, V. V. Petrunyaka, G. A. Osipov, S. S. Belyaev, and M. V. Ivanov (2001). "Taxonomic study of aerobic thermophilic bacilli: descriptions of Geobacillus subterraneus gen. nov., sp. nov. and Geobacillus uzenensis sp. nov. from petroleum reservoirs and transfer of Bacillus stearothermophilus, Bacillus thermocatenulatus, Bacillus thermoleovorans, Bacillus kaustophilus, Bacillus thermodenitrificans to Geobacillus as the new combinations G. stearothermophilus, G. th.". International Journal of Systematic and Evolutionary Microbiology 51: 433–446. 
  5. ^ Mori Y, Hirano T, Notomi T (2006). "Sequence specific visual detection of LAMP reactions by addition of cationic polymers". BMC Biotechnol. 6: 3.