''Lactobacillus'' is a
genus of
Gram-positive,
aerotolerant anaerobes or
microaerophilic, rod-shaped, non-
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
-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 below).
''Lactobacillus'' species constitute a significant component of the human and animal
microbiota
Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found t ...
at a number of body sites, such as the
digestive system
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...
, and the female
genital system. In women of European ancestry, ''Lactobacillus'' species are normally a major part of the
vaginal microbiota.
''Lactobacillus'' forms
biofilms in the vaginal and
gut microbiota
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut m ...
, allowing them to persist during harsh environmental conditions and maintain ample populations.
''Lactobacillus'' exhibits a
mutualistic relationship with the human body, as it protects the host against potential invasions by
pathogens, and in turn, the host provides a source of nutrients.
Lactobacilli are among the most common
probiotic found in food such as yogurt, and it is diverse in its application to maintain human well-being, as it can help treat diarrhea, vaginal infections, and skin disorders such as eczema.
Metabolism
Lactobacilli are
homofermentative, i.e. hexoses are metabolised by
glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH ...
to lactate as major end product, or heterofermentative, i.e. hexoses are metabolised by the
Phosphoketolase pathway to lactate, CO
2 and acetate or ethanol as major end products.
Most lactobacilli are
aerotolerant and some species respire if heme and menaquinone are present in the growth medium.
Aerotolerance of lactobacilli is
manganese-dependent and has been explored (and explained) in ''Lactiplantibacillus plantarum'' (previously ''
Lactobacillus plantarum)''.
Lactobacilli generally do not require
iron for growth.
The
Lactobacillaceae are the only family of the
lactic acid bacteria (LAB) that includes homofermentative and heterofermentative organisms; in the ''Lactobacillaceae'', homofermentative or heterofermentative metabolism is shared by all strains of a genus.
''Lactobacillus'' species are all homofermentative, do not express pyruvate formate lyase, and most species do not ferment pentoses.
In ''L. crispatus'', pentose metabolism is strain specific and acquired by lateral gene transfer.
Genomes
The genomes of lactobacilli are highly variable, ranging in size from 1.2 to 4.9 Mb (megabases).
Accordingly, the number of protein-coding genes ranges from 1,267 to about 4,758 genes (in ''Fructilactobacillus sanfranciscensis'' and ''Lentilactobacillus parakefiri'', respectively). Even within a single species there can be substantial variation. For instance, strains of
''L. crispatus'' have genome sizes ranging from 1.83 to 2.7 Mb, or 1,839 to 2,688
open reading frames. ''Lactobacillus'' contains a wealth of compound microsatellites in the coding region of the genome, which are imperfect and have variant motifs. Many lactobacilli also contain multiple plasmids. A recent study has revealed that plasmids encode the genes which are required for adaptation of lactobacilli to the given environment.
Species
The genus ''Lactobacillus'' comprises the following species:
* ''
Lactobacillus acetotolerans
''Lactobacillus acetotolerans'' (New Latin 'vinegar-tolerating milk-bacillus') is a species of gram positive bacteria in the genus ''Lactobacillus''. Discovered in rice wine vinegar, it has a very high tolerance for acetic acid. It can tolerate a ...
''
Entani et al. 1986
* ''
Lactobacillus acidophilus''
(Moro 1900) Hansen and Mocquot 1970 (Approved Lists 1980)
* "''Lactobacillus alvi''"
Kim et al. 2011
* ''
Lactobacillus amylolyticus
''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 di ...
''
Bohak et al. 1999
* ''
Lactobacillus amylovorus
''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 di ...
''
Nakamura 1981
* ''
Lactobacillus apis
''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 di ...
''
Killer et al. 2014
* "''Lactobacillus backi''"
Bohak et al. 2006
* ''
Lactobacillus bombicola
''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 diver ...
''
Praet et al. 2015
* ''
Lactobacillus colini
''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 di ...
''
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
''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 diver ...
''
Morita et al. 2010
* ''
Lactobacillus fornicalis
''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 di ...
''
Dicks et al. 2000
* ''
Lactobacillus gallinarum
''Lactobacillus gallinarum'' is a species in the genus '' Lactobacillus''. Its type strain is ATCC 33199.
''L. gallinarum'' is a native probiotic to chickens. ''L. gallinarum'' adheres to the epithelial cells of the crop, ileum, and ceca of br ...
''
Fujisawa et al. 1992
* ''
Lactobacillus gasseri
''Lactobacillus gasseri'' is a species in the genus ''Lactobacillus'' identified in 1980 by François Gasser and his associates. It is part of the vaginal flora. Its genome has been sequenced. ''L. gasseri'' is a normal inhabitant of the lower ...
''
Lauer and Kandler 1980
* ''
Lactobacillus gigeriorum
''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 di ...
''
Cousin et al. 2012
* "''Lactobacillus ginsenosidimutans''"
Jung et al. 2013
* ''
Lactobacillus hamsteri
''Lactobacillus'' is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-endospore, spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metaboli ...
''
Mitsuoka and Fujisawa 1988
* ''
Lactobacillus helsingborgensis
''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 di ...
''
Olofsson et al. 2014
* ''
Lactobacillus helveticus''
(Orla-Jensen 1919) Bergey et al. 1925 (Approved Lists 1980)
* ''
Lactobacillus hominis
''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 ...
''
Cousin et al. 2013
* ''
Lactobacillus iners
''Lactobacillus iners'' is a species in the genus ''Lactobacillus''. It is a Gram-positive, catalase
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes t ...
''
Falsen et al. 1999
* ''
Lactobacillus intestinalis
''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 di ...
''
(ex Hemme 1974) Fujisawa et al. 1990
* ''
Lactobacillus jensenii
''Lactobacillus jensenii'' is a normal inhabitant of the lower reproductive tract in healthy women. ''L. jensenii'' makes up 23% of vaginal microflora that is naturally occurring. It is also found on the skins of grapes at the time of their har ...
''
Gasser et al. 1970 (Approved Lists 1980)
* "''Lactobacillus jinshani''"
Yu et al. 2020
* ''
Lactobacillus johnsonii
''Lactobacillus johnsonii'' is a species in the genus ''Lactobacillus'' identified in 1980 by John L. Johnson, an American microbiologist and his associates. Its type strain is ATCC 33200. It is part of the healthy vaginal microbiota and has bee ...
''
Fujisawa et al. 1992
* ''
Lactobacillus kalixensis
''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 di ...
''
Roos et al. 2005
* ''
Lactobacillus kefiranofaciens
''Lactobacillus kefiranofaciens'' is a species of slime-forming, homofermentative, rod-shaped lactic acid bacteria first isolated from kefir grains, hence its name. Its type strain is WT-2B (ATCC 43761). Its genome has been sequenced.
References ...
''
Fujisawa et al. 1988
* ''
Lactobacillus kimbladii
''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 di ...
''
Olofsson et al. 2014
* ''
Lactobacillus kitasatonis
''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 di ...
''
Mukai et al. 2003
* ''
Lactobacillus kullabergensis
''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 di ...
''
Olofsson et al. 2014
* ''
Lactobacillus melliventris
''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 di ...
''
Olofsson et al. 2014
* ''
Lactobacillus mulieris
''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 di ...
''
Rocha et al. 2020
* ''
Lactobacillus nasalidis
''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 di ...
''
Suzuki-Hashido et al. 2021
* ''
Lactobacillus panisapium
''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 di ...
''
Wang et al. 2018
* ''
Lactobacillus paragasseri
''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 di ...
''
Tanizawa et al. 2018
* ''
Lactobacillus pasteurii
''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 ...
''
Cousin et al. 2013
* ''
Lactobacillus porci
''Lactobacillus porci'' is a species of bacteria that falls within the '' Lactobacillus'' genus. Species within this genus are typically facultative anaerobes, gram-positive rods, non-spore forming, and are able to produce lactic acid from fe ...
''
Kim et al. 2018
* ''
Lactobacillus psittaci
''Lactobacillus'' is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-endospore, spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metaboli ...
''
Lawson et al. 2001
* "''Lactobacillus raoultii''"
Nicaise et al. 2018
* ''
Lactobacillus rodentium
''Lactobacillus'' is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-endospore, spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metaboli ...
''
Killer et al. 2014
* ''
Lactobacillus rogosae
''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 diver ...
''
Holdeman and Moore 1974 (Approved Lists 1980)
* ''
Lactobacillus taiwanensis''
Wang et al. 2009
* "''
Lactobacillus thermophilus
"''Lactobacillus thermophilus''" is a gram-positive, non-motile, non-sporulating rod-shaped bacterium. It belongs to the genus '' Bacillus'', but has not been formally named or reclassified. Found mostly in pasteurized milk, the bacterium is rep ...
''"
Ayers and Johnson 1924
* "''Lactobacillus timonensis''"
Afouda et al. 2017
* ''
Lactobacillus ultunensis
''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 di ...
''
Roos et al. 2005
* ''
Lactobacillus xujianguonis
''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 di ...
''
Meng et al. 2020
Taxonomy
The genus ''Lactobacillus'' currently contains 44 species which are adapted to vertebrate hosts or to insects.
In recent years, other members of the genus ''Lactobacillus'' (formerly known as the ''Leuconostoc'' branch of ''Lactobacillus'') have been reclassified into the genera ''
Atopobium
''Atopobium'' is a genus of Actinomycetota, in the family Coriobacteriaceae. ''Atopobium'' species are anaerobic, Gram-positive rod-shaped or elliptical bacteria found as single elements or in pairs or short chains.
''Atopobium vaginae'' was di ...
'', ''
Carnobacterium
''Carnobacterium'' is a genus of Gram-positive bacteria within the family Carnobacteriaceae. ''C. divergens'' and ''C. maltaromaticum'' are found in the wild and in food products and can grow anaerobically. These species are not known to be patho ...
'', ''
Weissella
''Weissella'' is a genus of gram-positive bacteria placed within the family Lactobacillaceae, formerly considered species of the ''Leuconostoc paramesenteroides'' group. The morphology of ''Weissella'' species varies from spherical or lenticula ...
'', ''
Oenococcus'', and ''
Leuconostoc''. The ''
Pediococcus'' species ''
P. dextrinicus'' has been reclassified as a ''Lapidilactobacillus dextrinicus''
and most lactobacilli were assigned to ''
Paralactobacillus'' or one of the 23 novel genera of the ''Lactobacillaceae.
'' Two websites inform on the assignment of species to the novel genera or species (http://www.lactobacillus.uantwerpen.be/; http://www.lactobacillus.ualberta.ca/).
Phylogeny
The currently accepted taxonomy is based on the
List of Prokaryotic names with Standing in Nomenclature and the phylogeny is based on whole-genome sequences.
Human health
Vaginal tract
The female genital tract is one of the principal colonisation sites for
human microbiotic
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, an ...
, and there is interest in the relationship between their presence and human health, with a domination by a single species being correlated with general welfare and good outcomes in pregnancy. In around 70% of women, a ''Lactobacillus'' species is dominant, although that has been found to vary between American women of European origin and those of African origin, the latter group tending to have more diverse vaginal microbiota. Similar differences have also been identified in comparisons between Belgian and Tanzanian women.
Interactions with pathogens
Lactobacilli produce
hydrogen peroxide which inhibits the growth and
virulence of the fungal pathogen ''
Candida albicans'' ''
in vitro'' and ''
in vivo''.
In vitro studies have also shown that lactobacilli reduce the pathogenicity of ''C. albicans'' through the production of organic acids and certain metabolites.
Both the presence of metabolites, such as sodium butyrate, and the decrease in environmental pH caused by the organic acids reduce the growth of
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
e in ''C. albicans'', which reduces its pathogenicity.
Lactobacilli also reduce the pathogenicity of ''C. albicans'' by reducing ''C. albicans'' biofilm formation.
Biofilm formation is reduced by both the competition from lactobacilli, and the formation of defective biofilms which is linked to the reduced hypha growth mentioned earlier.
On the other hand, following
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
therapy, certain ''Candida'' species can suppress the regrowth of lactobacilli at body sites where they cohabitate, such as in the gastrointestinal tract.
In addition to its effects on ''C. albicans'', ''Lactobacillus'' sp. also interact with other pathogens. For example, ''
Limosilactobacillus reuteri
''Limosilactobacillus reuteri'' is a lactic acid bacterium found in a variety of natural environments, including the gastrointestinal tract of humans and other animals. It does not appear to be pathogenic and may have health effects.
Discove ...
'' (formerly ''Lactobacillus reuteri'') can inhibit the growth of many different bacterial species by using glycerol to produce the antimicrobial substance called
reuterin
Reuterin (3-hydroxypropionaldehyde) is the organic compound with the formula HOCH2CH2CHO. It is a bifunctional molecule, containing both a hydroxy and aldehyde functional groups.
The name reuterin is derived from ''Lactobacillus reuteri'', which ...
. Another example is ''
Ligilactobacillus salivarius
''Ligilactobacillus salivarius'' is a probiotic bacteria species that has been found to live in the gastrointestinal tract and exert a range of therapeutic properties including suppression of pathogenic bacteria.
Therapeutic research Irrit ...
(''formerly ''Lactobacillus salivarius''), which interacts with many pathogens through the production of salivaricin B, a bacteriocin.
Probiotics
Fermentive bacteria like
lactic acid bacteria (LAB) produce hydrogen peroxide which protects themselves from oxygen toxicity. The accumulation of hydrogen peroxide in growth media, and its antagonistic effects on ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...
'' and ''
Pseudomonas'', have been demonstrated by researchers. LAB cultures have been used as starter cultures to create fermented foods since the beginning of the 20th century.
Elie Metchnikoff won a Nobel prize in 1908 for his work on LAB.
Lactobacilli administered in combination with other
probiotics benefits cases of
irritable bowel syndrome (IBS), although the extent of efficacy is still uncertain.
The probiotics help treat IBS by returning homeostasis when the gut microbiota experiences unusually high levels of opportunistic bacteria.
In addition, lactobacilli can be administered as probiotics during cases of infection by the ulcer-causing bacterium
Helicobacter pylori.
''Helicobacter pylori'' is linked to cancer, and antibiotic resistance impedes the success of current antibiotic-based eradication treatments.
When probiotic lactobacilli are administered along with the treatment as an
adjuvant, its efficacy is substantially increased and side effects may be lessened.
Also, lactobacilli are used to help control urogenital and vaginal infections, such as
bacterial vaginosis (BV). ''Lactobacilli'' produce
bacteriocins to suppress pathogenic growth of certain bacteria,
as well as lactic acid and
H2O2 (hydrogen peroxide). Lactic acid lowers the vaginal pH to around 4.5 or less, hampering the survival of other bacteria, and H
2O
2 reestablishes the normal bacterial microbiota and normal vaginal pH.
In children, lactobacilli such as ''Lacticaseibacillus rhamnosus'' (previously ''
L. rhamnosus
''Lacticaseibacillus rhamnosus'' (previously ''Lactobacillus rhamnosus'') is a bacterium that originally was considered to be a subspecies of ''L. casei'', but genetic research found it to be a separate species in the ''L. casei'' clade, which a ...
'') 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
Cheese is a dairy product produced in wide ranges of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, ...
,
sauerkraut,
pickles,
beer,
cider
Cider ( ) is an alcoholic beverage made from the fermented juice of apples. Cider is widely available in the United Kingdom (particularly in the West Country) and the Republic of Ireland. The UK has the world's highest per capita consumption, ...
,
kimchi,
cocoa
Cocoa may refer to:
Chocolate
* Chocolate
* ''Theobroma cacao'', the cocoa tree
* Cocoa bean, seed of ''Theobroma cacao''
* Chocolate liquor, or cocoa liquor, pure, liquid chocolate extracted from the cocoa bean, including both cocoa butter and ...
,
kefir, and other
fermented foods, as well as
animal feeds
Animal feed is food given to domestic animals, especially livestock, in the course of animal husbandry. There are two basic types: fodder and forage. Used alone, the word ''feed'' more often refers to fodder. Animal feed is an important inpu ...
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
Sourdough or sourdough bread is a bread made by the fermentation of dough using wild lactobacillaceae and yeast. Lactic acid from fermentation imparts a sour taste and improves keeping qualities.
History
In the ''Encyclopedia of Food Microbio ...
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
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
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
Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for br ...
, 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
''Levilactobacillus brevis'' is a gram-positive, rod shaped species of lactic acid bacteria which is heterofermentative, creating CO2, lactic acid and acetic acid or ethanol during fermentation. ''L. brevis'' is the type species of the genus '' ...
'', are some of the most common beer spoilage organisms. They are, however, essential to the production of sour beers such as Belgian
lambic
Lambic () is a type of beer brewed in the Pajottenland region of Belgium southwest of Brussels and in Brussels itself since the 13th century. Types of lambic beers include gueuze, kriek lambic and framboise. Lambic differs from most other beers ...
s and American wild ales, giving the beer a distinct tart flavor.
See also
*
Lactobacillus L. anticaries
Lactobacillus L. anticaries is a bacterium created by the German chemical company BASF. This bacterium has been added to chewing gum, but it does not remove the need to brush one's teeth. ''L. anticaries'' eliminates the malignant bacteria in on ...
*
Lactic acid fermentation
*
MRS agar
* ''
Pediococcus''
*
Probiotics
*
Proteobiotics
*
Carbon monoxide-releasing molecules
References
External links
*
Lactobacillus at Milk the Funk Wiki''Lactobacillus'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Authority control
Lactobacillaceae
Food science
Gut flora bacteria
Garde manger
Gram-positive bacteria
Bacteria genera