B. acidiceler B. acidicola B. acidiproducens B. acidocaldarius B. acidoterrestris B. aeolius B. aerius B. aerophilus B. agaradhaerens B. agri B. aidingensis B. akibai B. alcalophilus B. algicola B. alginolyticus B. alkalidiazotrophicus B. alkalinitrilicus B. alkalisediminis B. alkalitelluris B. altitudinis B. alveayuensis B. alvei B. amyloliquefaciens
* _B. a._ subsp. _amyloliquefaciens_ * _B. a._ subsp. _plantarum_
B. aminovorans B. amylolyticus B. andreesenii B. aneurinilyticus B. anthracis B. aquimaris B. arenosi B. arseniciselenatis B. arsenicus B. aurantiacus B. arvi B. aryabhattai B. asahii B. atrophaeus B. axarquiensis B. azotofixans B. azotoformans B. badius B. barbaricus B. bataviensis B. beijingensis B. benzoevorans B. beringensis B. berkeleyi B. beveridgei B. bogoriensis B. boroniphilus B. borstelensis B. brevis Migula B. butanolivorans B. canaveralius B. carboniphilus B. cecembensis B. cellulosilyticus B. centrosporus B. cereus B. chagannorensis B. chitinolyticus B. chondroitinus B. choshinensis B. chungangensis B. cibi B. circulans B. clarkii B. clausii B. coagulans B. coahuilensis B. cohnii B. composti B. curdlanolyticus B. cycloheptanicus B. cytotoxicus B. daliensis B. decisifrondis B. decolorationis B. deserti B. dipsosauri B. drentensis B. edaphicus B. ehimensis B. eiseniae B. enclensis B. endophyticus B. endoradicis B. farraginis B. fastidiosus B. fengqiuensis B. firmus B. flexus B. foraminis B. fordii B. formosus B. fortis B. fumarioli B. funiculus B. fusiformis B. galactophilus B. galactosidilyticus B. galliciensis B. gelatini B. gibsonii B. ginsengi B. ginsengihumi B. ginsengisoli B. globisporus
* _B. g._ subsp. _globisporus_ * _B. g._ subsp. _marinus_
B. glucanolyticus B. gordonae B. gottheilii B. graminis B. halmapalus B. haloalkaliphilus B. halochares B. halodenitrificans B. halodurans B. halophilus B. halosaccharovorans B. hemicellulosilyticus B. hemicentroti B. herbersteinensis B. horikoshii B. horneckiae B. horti B. huizhouensis B. humi B. hwajinpoensis B. idriensis B. indicus B. infantis B. infernus B. insolitus B. invictae B. iranensis B. isabeliae B. isronensis B. jeotgali B. kaustophilus B. kobensis B. kochii B. kokeshiiformis B. koreensis B. korlensis B. kribbensis B. krulwichiae B. laevolacticus B. larvae B. laterosporus B. lautus B. lehensis B. lentimorbus B. lentus B. licheniformis B. ligniniphilus B. litoralis B. locisalis B. luciferensis B. luteolus B. luteus B. macauensis B. macerans B. macquariensis B. macyae B. malacitensis B. mannanilyticus B. marisflavi B. marismortui B. marmarensis B. massiliensis B. megaterium B. mesonae B. methanolicus B. methylotrophicus B. migulanus B. mojavensis B. mucilaginosus B. muralis B. murimartini B. mycoides B. naganoensis B. nanhaiensis B. nanhaiisediminis B. nealsonii B. neidei B. neizhouensis B. niabensis B. niacini B. novalis B. oceanisediminis B. odysseyi B. okhensis B. okuhidensis B. oleronius B. oryzaecorticis B. oshimensis B. pabuli B. pakistanensis B. pallidus B. pallidus B. panacisoli B. panaciterrae B. pantothenticus B. parabrevis B. paraflexus B. pasteurii B. patagoniensis B. peoriae B. persepolensis B. persicus B. pervagus B. plakortidis B. pocheonensis B. polygoni B. polymyxa B. popilliae B. pseudalcalophilus B. pseudofirmus B. pseudomycoides B. psychrodurans B. psychrophilus B. psychrosaccharolyticus B. psychrotolerans B. pulvifaciens B. pumilus B. purgationiresistens B. pycnus B. qingdaonensis B. qingshengii B. reuszeri B. rhizosphaerae B. rigui B. ruris B. safensis B. salarius B. salexigens B. saliphilus B. schlegelii B. sediminis B. selenatarsenatis B. selenitireducens B. seohaeanensis B. shacheensis B. shackletonii B. siamensis B. silvestris B. simplex B. siralis B. smithii B. soli B. solimangrovi B. solisalsi B. songklensis B. sonorensis B. sphaericus B. sporothermodurans B. stearothermophilus B. stratosphericus B. subterraneus B. subtilis
* _B. s._ subsp. _inaquosorum_ * _B. s._ subsp. _spizizenii_ * _B. s._ subsp. _subtilis_
B. taeanensis B. tequilensis B. thermantarcticus B. thermoaerophilus B. thermoamylovorans B. thermocatenulatus B. thermocloacae B. thermocopriae B. thermodenitrificans B. thermoglucosidasius B. thermolactis B. thermoleovorans B. thermophilus B. thermoruber B. thermosphaericus B. thiaminolyticus B. thioparans B. thuringiensis B. tianshenii B. trypoxylicola B. tusciae B. validus B. vallismortis B. vedderi B. velezensis B. vietnamensis B. vireti B. vulcani B. wakoensis B. weihenstephanensis B. xiamenensis B. xiaoxiensis _B. zhanjiangensis _
_ Gram stain of a Bacillus_ species
_BACILLUS_ is a genus of gram-positive , rod-shaped bacteria and a member of the phylum Firmicutes . _Bacillus_ species can be obligate aerobes (oxygen reliant), or facultative anaerobes (having the ability to be aerobic or anaerobic). They will test positive for the enzyme catalase when there has been oxygen used or present. Ubiquitous in nature, _Bacillus_ includes both free-living (nonparasitic) and parasitic pathogenic species. Under stressful environmental conditions, the bacteria can produce oval endospores that are not true 'spores', but to which the bacteria can reduce themselves and remain in a dormant state for very long periods. These characteristics originally defined the genus, but not all such species are closely related, and many have been moved to other genera of the Firmicutes.
Many species of _Bacillus_ can produce copious amounts of enzymes which are used in different industries. Some species can form intracellular inclusions of polyhydroxyalkanoates under certain adverse environmental conditions, as in a lack of elements such as phosphorus, nitrogen, or oxygen combined with an excessive supply of carbon sources.
_ B. subtilis _ has proved a valuable model for research. Other species of _Bacillus_ are important pathogens, causing anthrax and food poisoning .
* 1 Industrial significance * 2 Use as model organism * 3 Ecological significance * 4 Clinical significance * 5 Cell wall * 6 Phylogeny * 7 See also * 8 References * 9 External links
Many _Bacillus_ species are able to secrete large quantities of enzymes. _ Bacillus amyloliquefaciens _ is the source of a natural antibiotic protein barnase (a ribonuclease ), alpha amylase used in starch hydrolysis, the protease subtilisin used with detergents, and the BamH1 restriction enzyme used in DNA research.
A portion of the _
USE AS MODEL ORGANISM
_ Colonies of the model species
_Bacillus_ species are almost ubiquitous in nature, e.g. in soil, but also occur in extreme environments such as high pH (_B. alcalophilus _), high temperature (_B. thermophilus _), or high salt (_B. halodurans _). _ B. thuringiensis _ produces a toxin that can kill insects and thus has been used as insecticide.
Two _Bacillus_ species are considered medically significant: _B. anthracis _, which causes anthrax , and _B. cereus _, which causes food poisoning similar to that caused by _ Staphylococcus _. A third species, _ B. thuringiensis _, is an important insect pathogen, and is sometimes used to control insect pests. The type species is _B. subtilis_, an important model organism . It is also a notable food spoiler, causing ropiness in bread and related food. Some environmental and commercial strains of _B. coagulans _ may play a role in food spoilage of highly acidic, tomato-based products.
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. 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 it bulge.
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 composed of teichoic and teichuronic acids. _B. subtilis_ is the first bacterium for which the role of an actin -like cytoskeleton in cell shape determination and peptidoglycan synthesis was identified, and for which the entire set of peptidoglycan-synthesizing enzymes was localised. The role of the cytoskeleton in shape generation and maintenance is important
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 _. _Bacillus_ 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 _ and _ Vibrio _, the 266 species of _Bacillus_ are ubiquitous. The genus has a very large ribosomal 16S diversity and is environmentally diverse.
Several studies have tried to reconstruct the phylogeny of the genus. The _Bacillus_-specific study with the most diversity covered is by Xu and Cote using 16S and the ITS regions, where they divide the genus into 10 groups, which includes the nested genera _ Paenibacillus , Brevibacillus , Geobacillus , Marinibacillus_ and _ Virgibacillus _. However, the tree constructed by the living tree project , a collaboration between ARB-Silva and LPSN where a 16S (and 23S if available) tree of all validated species was constructed, 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 _ and others. A gene concatenation study found similar results to Xu and Cote, but with a much more limited number of species in terms of groups, but used _Listeria_ as an outgroup, so in light of the ARB tree, it may be "inside-out".
One clade, formed by _B. anthracis_, _B. cereus_, _B. mycoides_, _B.
pseudomycoides_, _B. thuringiensis_, and _B. weihenstephanensis_ under
current 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
_ Bacillus pumilus _
_ Geobacillus kaustophilus _
_Bacillus_ sp. m3-13
_Bacillus_ sp. NRRLB-14911
_ Bacillus clausii _
Phylogeny of the genus _Bacillus_ according to
* ^ _A_ _B_ (in German) Cohn F.: _Untersuchungen über Bakterien.
Beitrage zur Biologie der Pflanzen_ Heft 2, 1872, 1, 127-224.
* ^ 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
* ^ Joan L. Slonczewski Ray CG, eds. (2004). _Sherris Medical
Microbiology_ (4th ed.). McGraw Hill. ISBN 0-8385-8529-9 .