(Latin "stick") is a genus
, rod-shaped bacteria
, a member of the phylum Firmicutes
, with 266 named species
. The term is also used to describe the shape (rod) of certain bacteria; and the plural Bacilli
is the name of the class
of bacteria to which this genus belongs. Bacillus
species can be either obligate aerobes
dependent; or facultative anaerobes
: having the ability to continue living in the absence of oxygen. Cultured Bacillus
species test positive for the enzyme catalase
if oxygen has been used or is present.
can reduce themselves to oval endospores
and can remain in this dormant state for years. The endospore of one species from Morocco is reported to have survived being heated to 420 °C.
Endospore formation is usually triggered by a lack of nutrients: the bacterium divides within its cell wall, and one side then engulfs the other. They are not true spores
(i.e., not an offspring).
Endospore formation originally defined the genus, but not all such species are closely related, and many species have been moved to other genera of the Firmicutes
Only one endospore is formed per cell. The spores are resistant to heat, cold, radiation, desiccation, and disinfectants. Bacillus anthracis
needs oxygen to sporulate; this constraint has important consequences for epidemiology and control. In vivo, B. anthracis
produces a polypeptide (polyglutamic acid) capsule that kills it from phagocytosis. The genera Bacillus
constitute the family Bacillaceae
. Species are identified by using morphologic and biochemical criteria.
Because the spores of many Bacillus
species are resistant to heat, radiation, disinfectants, and desiccation, they are difficult to eliminate from medical and pharmaceutical materials and are a frequent cause of contamination. Not only are they resistant to heat, radiation, etc., but they are also resistant to chemicals such as antibiotics.
This resistance allows them to survive for many years and especially in a controlled environment. Bacillus
species are well known in the food industries as troublesome spoilage organisms.
The cell wall of Bacillus
is a structure on the outside of the cell that forms the second barrier between the bacterium and the environment, and at the same time maintains the rod shape and withstands the pressure generated by the cell's turgor
. The cell wall is made of teichoic
and teichuronic acids. B. subtilis
is the first bacterium for which the role of an actin
in cell shape determination and peptidoglycan synthesis was identified and for which the entire set of peptidoglycan-synthesizing enzymes was localized. The role of the cytoskeleton in shape generation and maintenance is important.
species are rod-shaped, endospore-forming aerobic or facultatively anaerobic, Gram-positive bacteria; in some species cultures may turn Gram-negative with age. The many species of the genus exhibit a wide range of physiologic abilities that allow them to live in every natural environment. Only one endospore is formed per cell. The spores are resistant to heat, cold, radiation, desiccation, and disinfectants.
Origin of name
The genus Bacillus
was named in 1835 by Christian Gottfried Ehrenberg
, to contain rod-shaped (bacillus) bacteria. He had seven years earlier named the genus Bacterium
was later amended by Ferdinand Cohn
to further describe them as spore-forming, Gram-positive, aerobic or facultatively anaerobic bacteria.
Like other genera associated with the early history of microbiology, such as Pseudomonas
, the 266 species of Bacillus
The genus has a very large ribosomal 16S
Isolation and identification
An easy way to isolate Bacillus
species is by placing nonsterile soil in a test tube
with water, shaking, placing in melted mannitol salt agar
, and incubating at room temperature for at least a day. Cultured colonies are usually large, spreading, and irregularly shaped.
Under the microscope, the Bacillus
cells appear as rods, and a substantial portion of the cells usually contain oval endospores
at one end, making them bulge.
Three proposals have been presented as representing the phylogeny of the genus Bacillus
. The first proposal, presented in 2003, is a Bacillus
-specific study, with the most diversity covered using 16S and the ITS regions. It divides the genus into 10 groups. This includes the nested genera Paenibacillus, Brevibacillus, Geobacillus, Marinibacillus
The second proposal, presented in 2008,
constructed a 16S (and 23S if available) tree of all validated species.
The genus Bacillus
contains a very large number of nested taxa and majorly in both 16S and 23S. It is paraphyletic
to the Lactobacillales
(Lactobacillus, Streptococcus, Staphylococcus, Listeria
, etc.), due to Bacillus coahuilensis
A third proposal, presented in 2010, was a gene concatenation
study, and found results similar to the 2008 proposal, but with a much more limited number of species in terms of groups.
(This scheme used Listeria
as an outgroup, so in light of the ARB tree, it may be "inside-out").
One clade, formed by Bacillus anthracis
, Bacillus cereus
, Bacillus mycoides
, Bacillus pseudomycoides
, Bacillus thuringiensis
, and Bacillus weihenstephanensis
under the 2011 classification standards, should be a single species (within 97% 16S identity), but due to medical reasons, they are considered separate species:34–35
(an issue also present for four species of Shigella
and Escherichia coli
Phylogeny of the genus Bacillus
according to 
Ecological and clinical significance
A portion of the Bacillus thuringiensis
genome was incorporated into corn (and cotton) crops. The resulting GMOs
are resistant to some insect pests. Bacillus
species continue to be dominant bacterial workhorses in microbial fermentations. Bacillus subtilis
(natto) is the key microbial participant in the ongoing production of the soya-based traditional natto fermentation, and some Bacillus
species are on the Food and Drug Administration's GRAS (generally regarded as safe) list. The capacity of selected Bacillus
strains to produce and secrete large quantities (20-25 g/L) of extracellular enzymes has placed them among the most important industrial enzyme producers. The ability of different species to ferment in the acid, neutral, and alkaline pH ranges, combined with the presence of thermophiles in the genus, has led to the development of a variety of new commercial enzyme products with the desired temperature, pH activity, and stability properties to address a variety of specific applications. Classical mutation and (or) selection techniques, together with advanced cloning and protein engineering strategies, have been exploited to develop these products. Efforts to produce and secrete high yields of foreign recombinant proteins in Bacillus
hosts initially appeared to be hampered by the degradation of the products by the host proteases. Recent studies have revealed that the slow folding of heterologous proteins at the membrane-cell wall interface of Gram-positive bacteria renders them vulnerable to attack by wall-associated proteases. In addition, the presence of thiol-disulphide oxidoreductases in B. subtilis may be beneficial in the secretion of disulphide-bond-containing proteins. Such developments from our understanding of the complex protein translocation machinery of Gram-positive bacteria should allow the resolution of current secretion challenges and make Bacillus
species preeminent hosts for heterologous protein production. Bacillus
strains have also been developed and engineered as industrial producers of nucleotides, the vitamin riboflavin, the flavor agent ribose, and the supplement poly-gamma-glutamic acid. With the recent characterization of the genome of B. subtilis
168 and of some related strains, Bacillus
species are poised to become the preferred hosts for the production of many new and improved products as we move through the genomic and proteomic era.
Use as model organism
is one of the best understood prokaryotes, in terms of molecular and cellular biology. Its superb genetic amenability and relatively large size have provided the powerful tools required to investigate a bacterium from all possible aspects. Recent improvements in fluorescent microscopy
techniques have provided novel insight into the dynamic structure of a single cell organism. Research on B. subtilis
has been at the forefront of bacterial molecular biology and cytology, and the organism is a model for differentiation, gene/protein regulation, and cell cycle events in bacteria.
- ^ Turnbull PCB (1996). "Bacillus". In Baron S; et al. (eds.). Bacillus. In: Barron's Medical Microbiology (4th ed.). Univ of Texas Medical Branch. ISBN 978-0-9631172-1-2.
- ^ "Turn up the Heat: Bacterial Spores Can Take Temperatures in the Hundreds of Degrees".
- ^ "Bacterial Endospores". Cornell University College of Agriculture and Life Sciences, Department of Microbiology. Retrieved October 21, 2018.
- ^ Madigan M; Martinko J, eds. (2005). Brock Biology of Microorganisms (11th ed.). Prentice Hall. ISBN 978-0-13-144329-7.
- ^ a b chttps://www.ncbi.nlm.nih.gov/books/NBK7699/
- ^ a b Christie, Graham; Setlow, Peter (2020-10-01). "Bacillus spore germination: Knowns, unknowns and what we need to learn". Cellular Signalling. 74: 109729. doi:10.1016/j.cellsig.2020.109729. ISSN 0898-6568. PMID 32721540.
- ^ Nigris, Sebastiano; Baldan, Enrico; Tondello, Alessandra; Zanella, Filippo; Vitulo, Nicola; Favaro, Gabriella; Guidolin, Valerio; Bordin, Nicola; Telatin, Andrea; Barizza, Elisabetta; Marcato, Stefania; Zottini, Michela; Squartini, Andrea; Valle, Giorgio; Baldan, Barbara (2018). "Biocontrol traits of Bacillus licheniformis GL174, a culturable endophyte of Vitis vinifera cv. Glera". BMC Microbiology. 18 (1): 133. doi:10.1186/s12866-018-1306-5. PMC 6192205. PMID 30326838.
- ^ Favaro, Gabriella; Bogialli, Sara; Di Gangi, Iole Maria; Nigris, Sebastiano; Baldan, Enrico; Squartini, Andrea; Pastore, Paolo; Baldan, Barbara (2016). "Characterization of lipopeptides produced by Bacillus licheniformisusing liquid chromatography with accurate tandem mass spectrometry". Rapid Communications in Mass Spectrometry. 30 (20): 2237–2252. doi:10.1002/rcm.7705. PMID 27487987.
- ^ (in German) Cohn F.: Untersuchungen über Bakterien. Beitrage zur Biologie der Pflanzen Heft 2, 1872, 1, 127–224.
- ^ Bacillus entry in LPSN; Euzéby, J.P. (1997). "List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet". International Journal of Systematic and Evolutionary Microbiology. 47 (2): 590–2. doi:10.1099/00207713-47-2-590. PMID 9103655.
- ^ Xu, D.; Cote, J. -C. (2003). "Phylogenetic relationships between Bacillus species and related genera inferred from comparison of 3' end 16S rDNA and 5' end 16S-23S ITS nucleotide sequences". International Journal of Systematic and Evolutionary Microbiology. 53 (3): 695–704. doi:10.1099/Ijs.0.02346-0. PMID 12807189.
- ^ http://www.arb-silva.de/fileadmin/silva_databases/living_tree/LTP_release_104/LTPs104_SSU_tree.pdf
- ^ Yarza, P.; Richter, M.; Peplies, J. R.; Euzeby, J.; Amann, R.; Schleifer, K. H.; Ludwig, W.; Glöckner, F. O.; Rosselló-Móra, R. (2008). "The All-Species Living Tree project: A 16S rRNA-based phylogenetic tree of all sequenced type strains". Systematic and Applied Microbiology. 31 (4): 241–250. doi:10.1016/j.syapm.2008.07.001. hdl:10261/103580. PMID 18692976.
- ^ Yarza, P.; Ludwig, W.; Euzéby, J.; Amann, R.; Schleifer, K. H.; Glöckner, F. O.; Rosselló-Móra, R. (2010). "Update of the All-Species Living Tree Project based on 16S and 23S rRNA sequence analyses". Systematic and Applied Microbiology. 33 (6): 291–299. doi:10.1016/j.syapm.2010.08.001. hdl:10261/54801. PMID 20817437.
- ^ a b Alcaraz, L.; Moreno-Hagelsieb, G.; Eguiarte, L. E.; Souza, V.; Herrera-Estrella, L.; Olmedo, G. (2010). "Understanding the evolutionary relationships and major traits of Bacillus through comparative genomics". BMC Genomics. 11: 332. doi:10.1186/1471-2164-11-332. PMC 2890564. PMID 20504335. 1471216411332.
- ^ Ole Andreas Økstad and Anne-Brit Kolstø Chapter 2: "Genomics of Bacillus Species" in M. Wiedmann, W. Zhang (eds.), Genomics of Foodborne Bacterial Pathogens, 29 Food Microbiology and Food Safety. Springer Science+Business Media, LLC 2011 DOI 10.1007/978-1-4419-7686-4_2
- ^ Brenner (D.J.): Family I. Enterobacteriaceae Rahn 1937, Nom. fam. cons. Opin. 15, Jud. Com. 1958, 73; Ewing, Farmer, and Brenner 1980, 674; Judicial Commission 1981, 104. In: N.R. Krieg and J.G. Holt (eds), Bergey's Manual of Systematic Bacteriology, first edition, vol. 1, The Williams & Wilkins Co, Baltimore, 1984, pp. 408-420
- ^ Loshon, Charles A.; Beary, Katherine E.; Gouveia, Kristine; Grey, Elizabeth Z.; Santiago-Lara, Leticia M.; Setlow, Peter (March 1998). "Nucleotide sequence of the sspE genes coding for γ-type small, acid-soluble spore proteins from the round-spore-forming bacteria Bacillus aminovorans, Sporosarcina halophila and S. ureae". Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression. 1396 (2): 148–152. doi:10.1016/S0167-4781(97)00204-2. PMID 9540829.
- ^ Joan L. Slonczewski & John W. Foster (2011), Microbiology: An Evolving Science (2nd Edition), Norton
- ^ Jeong, Haeyoung; Jeong, Da-Eun; Kim, Sun Hong; Song, Geun Cheol; Park, Soo-Young; Ryu, Choong-Min; Park, Seung-Hwan; Choi, Soo-Keun (2012-08-01). "Draft Genome Sequence of the Plant Growth-Promoting Bacterium Bacillus siamensis KCTC 13613T". Journal of Bacteriology. 194 (15): 4148–4149. doi:10.1128/JB.00805-12. ISSN 0021-9193. PMC 3416560. PMID 22815459.
- ^ Keen, E; Bliskovsky, V; Adhya, S; Dantas, G (2017). "Draft genome sequence of the naturally competent Bacillus simplex strain WY10". Genome Announcements. 5 (46): e01295–17. doi:10.1128/genomeA.01295-17. PMC 5690344. PMID 29146837.
- ^ Ryan KJ; Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 978-0-8385-8529-0.
- ^ Schallmey, M.; Singh, A.; Ward, O. P. (2004). "Developments in the use of Bacillus species for industrial production". Canadian Journal of Microbiology. 50 (1): 1–17. doi:10.1139/w03-076. PMID 15052317.
- ^ Graumann P, ed. (2012). Bacillus: Cellular and Molecular Biology (2nd ed.). Caister Academic Press. ISBN 978-1-904455-97-4. .
- ^ Ash, Carol; Priest, Fergus G.; Collins, M. David (1994). "Molecular identification of rRNA group 3 bacilli (Ash, Farrow, Wallbanks and Collins) using a PCR probe test". Antonie van Leeuwenhoek. 64 (3–4): 253–260. doi:10.1007/BF00873085. PMID 8085788. S2CID 7391845.
- ^ Heyndrickx, M.; Lebbe, L.; Kersters, K.; De Vos, P.; Forsyth, G.; Logan, N. A. (1 January 1998). "Virgibacillus: a new genus to accommodate Bacillus pantothenticus (Proom and Knight 1950). Emended description of Virgibacillus pantothenticus". International Journal of Systematic Bacteriology. 48 (1): 99–106. doi:10.1099/00207713-48-1-99.
Wikimedia Commons has media related to Bacillus
genomes and related information at PATRIC
, a Bioinformatics Resource Center funded by NIAID
Last edited on 29 May 2021, at 21:34
Content is available under CC BY-SA 3.0
unless otherwise noted.