Lactobacillus facts for kids
Quick facts for kids Lactobacillus |
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| Lactobacillus sp. near a squamous epithelial cell | |
Scientific classification  |
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| Unrecognized taxon (fix): | Lactobacillus |
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| Lactobacillus delbrueckii (Leichmann 1896) Beijerinck 1927 (Approved Lists 1980)
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Lactobacillus is a genus of gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus Lactobacillus comprised over 260 phylogenetically, ecologically, and metabolically diverse species; a taxonomic revision of the genus assigned lactobacilli to 25 genera (see § Taxonomy below).
Lactobacillus species constitute a significant component of the human and animal microbiota at a number of body sites, such as the digestive system, and the female genital system.
Species
The genus Lactobacillus comprises the following species:
- Lactobacillus acetotolerans Entani et al. 1986
- Lactobacillus acidophilus (Moro 1900) Hansen and Mocquot 1970 (Approved Lists 1980)
- "Lactobacillus alvi" Kim et al. 2011
- Lactobacillus amylolyticus Bohak et al. 1999
- Lactobacillus amylovorus Nakamura 1981
- Lactobacillus apis Killer et al. 2014
- "Lactobacillus backi" Bohak et al. 2006
- Lactobacillus bombicola Praet et al. 2015
- Lactobacillus colini Zhang et al. 2017
- Lactobacillus crispatus (Brygoo and Aladame 1953) Moore and Holdeman 1970 (Approved Lists 1980)
- Lactobacillus delbrueckii (Leichmann 1896) Beijerinck 1901 (Approved Lists 1980)
- Lactobacillus equicursoris Morita et al. 2010
- Lactobacillus fornicalis Dicks et al. 2000
- Lactobacillus gallinarum Fujisawa et al. 1992
- Lactobacillus gasseri Lauer and Kandler 1980
- Lactobacillus gigeriorum Cousin et al. 2012
- "Lactobacillus ginsenosidimutans" Jung et al. 2013
- Lactobacillus hamsteri Mitsuoka and Fujisawa 1988
- Lactobacillus helsingborgensis Olofsson et al. 2014
- Lactobacillus helveticus (Orla-Jensen 1919) Bergey et al. 1925 (Approved Lists 1980)
- Lactobacillus hominis Cousin et al. 2013
- Lactobacillus iners Falsen et al. 1999
- Lactobacillus intestinalis (ex Hemme 1974) Fujisawa et al. 1990
- Lactobacillus jensenii Gasser et al. 1970 (Approved Lists 1980)
- "Lactobacillus jinshani" Yu et al. 2020
- Lactobacillus johnsonii Fujisawa et al. 1992
- Lactobacillus kalixensis Roos et al. 2005
- Lactobacillus kefiranofaciens Fujisawa et al. 1988
- Lactobacillus kimbladii Olofsson et al. 2014
- Lactobacillus kitasatonis Mukai et al. 2003
- Lactobacillus kullabergensis Olofsson et al. 2014
- Lactobacillus melliventris Olofsson et al. 2014
- Lactobacillus mulieris Rocha et al. 2020
- Lactobacillus nasalidis Suzuki-Hashido et al. 2021
- Lactobacillus panisapium Wang et al. 2018
- Lactobacillus paragasseri Tanizawa et al. 2018
- Lactobacillus pasteurii Cousin et al. 2013
- Lactobacillus porci Kim et al. 2018
- Lactobacillus psittaci Lawson et al. 2001
- "Lactobacillus raoultii" Nicaise et al. 2018
- Lactobacillus rodentium Killer et al. 2014
- Lactobacillus rogosae Holdeman and Moore 1974 (Approved Lists 1980)
- Lactobacillus taiwanensis Wang et al. 2009
- "Lactobacillus thermophilus" Ayers and Johnson 1924
- "Lactobacillus timonensis" Afouda et al. 2017
- Lactobacillus ultunensis Roos et al. 2005
- Lactobacillus xujianguonis Meng et al. 2020
Human health
Probiotics
Lactobacilli administered in combination with other probiotics benefits cases of irritable bowel syndrome (IBS), although the extent of efficacy is still uncertain.
In children, lactobacilli such as Lacticaseibacillus rhamnosus (previously L. rhamnosus) are associated with a reduction of atopic eczema, also known as dermatitis, due to anti-inflammatory cytokines secreted by this probiotic bacteria. In addition, lactobacilli with other probiotic organisms in ripened milk and yogurt aid development of immunity in the mucous intestine in humans by raising the number of LgA (+).
Oral health
Some lactobacilli have been associated with cases of dental caries (cavities). Lactic acid can corrode teeth, and the Lactobacillus count in saliva has been used as a "caries test" for many years. Lactobacilli characteristically cause existing carious lesions to progress, especially those in coronal caries. The issue is, however, complex, as recent studies show probiotics can allow beneficial lactobacilli to populate sites on teeth, preventing streptococcal pathogens from taking hold and inducing dental decay. The scientific research of lactobacilli in relation to oral health is a new field and only a few studies and results have been published. Some studies have provided evidence of certain Lactobacilli which can be a probiotic for oral health. Some species, but not all, show evidence in defense to dental caries. Due to these studies, there have been applications of incorporating such probiotics in chewing gum and lozenges. There is also evidence of certain Lactobacilli that are beneficial in the defense of periodontal disease such as gingivitis and periodontitis.
Food production
Lactobacilli comprise most food fermenting lactic acid bacteria and are used as starter cultures in industry for controlled fermentation in the production of wine, yogurt, cheese, sauerkraut, pickles, beer, cider, kimchi, cocoa, kefir, and other fermented foods, as well as animal feeds and the bokashi soil amendment. Lactobacillus species are dominant in yogurt, cheese, and sourdough fermentations. The antibacterial and antifungal activity of lactobacilli relies on production of bacteriocins and low molecular weight compounds that inhibits these microorganisms.
Sourdough bread is made either spontaneously, by taking advantage of the bacteria naturally present in flour, or by using a "starter culture", which is a symbiotic culture of yeast and lactic acid bacteria growing in a water and flour medium. The bacteria metabolize sugars into lactic acid, which lowers the pH of their environment and creates the signature sourness associated with yogurt, sauerkraut, etc.
In many traditional pickling processes, vegetables are submerged in brine, and salt-tolerant lactobacilli feed on natural sugars found in the vegetables. The resulting mix of salt and lactic acid is a hostile environment for other microbes, such as fungi, and the vegetables are thus preserved—remaining edible for long periods.
Lactobacilli, especially pediococci and L. brevis, are some of the most common beer spoilage organisms. They are, however, essential to the production of sour beers such as Belgian lambics and American wild ales, giving the beer a distinct tart flavor.
See also
In Spanish: Lactobacillus para niños
- Lactobacillus L. anticaries
- Lactic acid fermentation
- MRS agar
- Pediococcus
- Probiotics
- Proteobiotics
- Carbon monoxide-releasing molecules
