Bacillus
Bacillus | |
---|---|
Bacillus subtilis, stained | |
Scientific classification | |
Domain: | Bacteria |
Phylum: | Bacillota |
Class: | Bacilli |
Order: | Bacillales |
Family: | Bacillaceae |
Genus: | Bacillus Cohn |
Species | |
Bacillus (Latin "stick") is a
Bacillus 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.[2] 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).[3] 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 Bacillota.[4] 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.[5] In vivo, B. anthracis produces a polypeptide (polyglutamic acid) capsule that kills it from phagocytosis.[5] The genera Bacillus and Clostridium constitute the family Bacillaceae. Species are identified by using morphologic and biochemical criteria.[1] 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.[6] This resistance allows them to survive for many years and especially in a controlled environment.[6] Bacillus species are well known in the food industries as troublesome spoilage organisms.[1]
Ubiquitous in nature, Bacillus includes symbiotic (sometimes referred to as endophytes) as well as independent species. Two species are medically significant: B. anthracis causes anthrax;[7] and B. cereus causes food poisoning.[8]
Many species of Bacillus can produce copious amounts of enzymes, which are used in various industries, such as in the production of
Structure
Cell wall
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
Bacillus 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.[1]
Origin of name
The genus Bacillus was named in 1835 by
Isolation and identification
Established methods for isolating Bacillus species for culture primarily involve suspension of sampled soil in distilled water, heat shock to kill off vegetative cells leaving primarily viable spores in the sample, and culturing on agar plates with further tests to confirm the identity of the cultured colonies.[17] Additionally, colonies which exhibit characteristics typical of Bacillus bacteria can be selected from a culture of an environmental sample which has been significantly diluted following heat shock or hot air drying to select potential Bacillus bacteria for testing.[18]
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.[19]
Characteristics of Bacillus spp.
S.I. Paul et al. (2021)[11] isolated and identified multiple strains of Bacillus subtilis (strains WS1A, [20] YBS29,[21] KSP163A,[22] OA122,[23] ISP161A,[24] OI6,[25] WS11,[26] KSP151E,[27] and S8,[28]) from marine sponges of the Saint Martin's Island Area of the Bay of Bengal, Bangladesh. Based on their study, colony, morphological, physiological, and biochemical characteristics of Bacillus spp. are shown in the Table below.[11]
Test type | Test | Characteristics |
Colony characters | Size | Medium |
Type | Round | |
Color | Whitish | |
Shape | Convex | |
Morphological characters | Shape | Rod |
Physiological characters | Motility | + |
Growth at 6.5% NaCl | + | |
Biochemical characters | Gram's staining | + |
Oxidase | - | |
Catalase | + | |
Oxidative-Fermentative | O/F | |
Motility | + | |
Methyl Red | + | |
Voges-Proskauer | - | |
Indole | - | |
H2S Production | +/– | |
Urease | - | |
Nitrate reductase | + | |
β-Galactosidase | + | |
Hydrolysis of | Gelatin | + |
Aesculin | + | |
Casein | + | |
Tween 40 | + | |
Tween 60 | + | |
Tween 80 | + | |
Acid production from | Glycerol | + |
Galactose | + | |
D-Glucose | + | |
D-Fructose | + | |
D-Mannose | + | |
Mannitol | + | |
N-Acetylglucosamine | + | |
Amygdalin | + | |
Maltose | + | |
D-Melibiose | + | |
D-Trehalose | + | |
Glycogen | + | |
D-Turanose | + |
Note: + = Positive, – =Negative, O= Oxidative, F= Fermentative
Phylogeny
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 and Virgibacillus.[29]
The second proposal, presented in 2008,
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.[34] (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[35] (an issue also present for four species of Shigella and Escherichia coli).[36]
A phylogenomic study of 1104 Bacillus proteomes was based on 114 core proteins and delineated the relationships among the various species, defined as Bacillus from the NCBI taxonomy.[37] The various strains were clustered into species, based on Average Nucleotide identity (ANI) values, with a species cutoff of 95%.[37]
Bacillus phylogenetics | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Phylogeny of the genus Bacillus according to [34] |
Species
- B. Symun
- B. acidicola
- B. acidiproducens
- B. acidocaldarius
- B. acidoterrestris
- B. aeolius
- B. aerius
- B. aerophilus
- B. agaradhaerens
- B. agri
- B. aidingensis
- B. akibai
- B. albus
- B. alcalophlus
- 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[38]
- 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
- 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. filobacterium rodentuim
- B. firmus
- B. flexus
- B. foraminis
- B. fordii
- B. formosus
- B. fortis
- B. fumarioli
- B. funiculus
- B. fusiformis
- B. gaemokensis
- B. galactophilus
- B. galactosidilyticus
- B. galliciensis
- B. gelatini
- B. gibsonii
- B. ginsengi
- B. ginsengihumi
- B. ginsengisoli
- B. glucanolyticus
- B. gordonae
- B. gottheilii
- B. graminis
- B. halmapalus
- B. haloalkaliphilus
- B. halochares
- B. halodenitrificans
- B. halodurans
- B. halophilus
- B. halosaccharovorans
- B. haynesii
- 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. mesentericus"
- 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. thermoproteolyticus
- 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. xiamenensis
- B. xiaoxiensis
- B. zanthoxyli
- B. zhanjiangensis
Ecological and clinical significance
Bacillus species are ubiquitous in nature, e.g. in soil. They can occur in extreme environments such as high pH (
- Two Bacillus species are medically significant: B. anthracis, which causes anthrax; and B. cereus, which causes food poisoning, with symptoms similar to that caused by Staphylococcus.[47]
- B. cereus produces toxins which cause two different set of symptoms:
- emetic toxin which can cause vomiting and nausea
- diarrhea
- B. cereus produces toxins which cause two different set of symptoms:
- B. thuringiensis is an important insectpathogen, and is sometimes used to control insect pests.
- B. subtilis is an important model organism. It is also a notable food spoiler, causing ropiness in bread and related food.
- B. subtilis can also produce and secrete antibiotics.
- Some environmental and commercial strains of B. coagulansmay play a role in food spoilage of highly acidic, tomato-based products.
Industrial significance
Many Bacillus species are able to
A portion of the
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.[citation needed]
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.[citation needed] 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.[citation needed]
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.[citation needed] 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.[citation needed] 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.[citation needed]
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.[48]
Use as model organism
See also
- Paenibacillus and Virgibacillus, genera of bacteria formerly included in Bacillus.[50][51]
References
- ^ PMID 21413260.
- S2CID 46935396.
- ^ "Bacterial Endospores". Cornell University College of Agriculture and Life Sciences, Department of Microbiology. Retrieved 21 October 2018.
- ISBN 978-0-13-144329-7.
- ^ PMID 21413260. Retrieved 2024-03-18.
- ^ PMID 32721540.
- PMID 12610093.
- PMID 15771198.
- PMID 30326838.
- PMID 27487987.
- ^ .
- PMID 32972930.
- PMID 16959967.
- ^ Cohn F (1872). "Untersuchungen über Bakterien" [Studies on Bacteria.]. Beiträge zur Biologie der Pflanzen [Contributions to the Biology of Plants] (in German). 2 (1): 127–224.
- .
- PMID 20418441.
- PMID 16347359.
- PMID 30733751.
- ISBN 978-1-257-42416-0.
- ^ "Bacillus subtilis strain WS1A". GenBank. U.S. National Library of Medicine. 19 May 2019.
- ^ "Bacillus subtilis strain YBS29". GenBank. U.S. National Library of Medicine. 19 June 2020.
- ^ "Bacillus subtilis strain KSP163A". GenBank. U.S. National Library of Medicine. 19 May 2019.
- ^ "Bacillus subtilis strain OA122". GenBank. U.S. National Library of Medicine. 20 June 2020.
- ^ "Bacillus subtilis strain ISP161A". GenBank. U.S. National Library of Medicine. 20 June 2020.
- ^ "Bacillus subtilis strain OI6". GenBank. U.S. National Library of Medicine. 19 June 2020.
- ^ "Bacillus subtilis strain WS11". GenBank. U.S. National Library of Medicine. 19 May 2019.
- ^ "Bacillus subtilis strain KSP151E". GenBank. U.S. National Library of Medicine. 19 June 2020.
- ^ "Bacillus subtilis strain S8". GenBank. U.S. National Library of Medicine. 20 June 2020.
- PMID 12807189.
- PMID 21497273. Archived from the original(PDF) on 23 September 2015.
- PMID 18692976.
- PMID 20817437.
- PMID 29915113.
- ^ PMID 20504335. 1471216411332.
- ISBN 978-1-4419-7686-4.
- ^ Brenner DJ (1984). "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 Krieg NR, Holt JG (eds.). Bergey's Manual of Systematic Bacteriology. Vol. 1 (first ed.). Baltimore: The Williams & Wilkins Co. pp. 408–420.
- ^ PMID 36144322.
- PMID 9540829.
- S2CID 19917931.
- PMID 12548929.
- PMID 25720168.
- PMID 31646970.
- ISSN 0929-1393.
- ^ Slonczewski JL, Foster JW (2011). Microbiology: An Evolving Science (2nd ed.). Norton.
- PMID 22815459.
- PMID 29146837.
- ISBN 978-0-8385-8529-0.
- PMID 15052317.
- ISBN 978-1-904455-97-4. [1].
- S2CID 7391845.
- .