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.
Probiotics are live microorganisms promoted with claims that they provide health benefits when consumed, generally by improving or restoring the gut microbiota. Probiotics are considered generally safe to consume, but may cause bacteria-host interactions and unwanted side effects in rare cases. There is some evidence that probiotics are beneficial for some conditions, such as helping to ease some symptoms of irritable bowel syndrome (IBS). However, many claimed health benefits, such as treating eczema, lack substantial scientific support.
Lactobacillus acidophilus is a rod-shaped, Gram-positive, homofermentative, anaerobic microbe first isolated from infant feces in the year 1900. The species is commonly found in humans, specifically the gastrointestinal tract and oral cavity as well as some speciality fermented foods such as fermented milk or yogurt, though it is not the most common species for this. The species most readily grows at low pH levels, and has an optimum growth temperature of 37 °C. Certain strains of L. acidophilus show strong probiotic effects, and are commercially used in dairy production. The genome of L. acidophilus has been sequenced.
Lactiplantibacillus plantarum is a widespread member of the genus Lactiplantibacillus and commonly found in many fermented food products as well as anaerobic plant matter. L. plantarum was first isolated from saliva. Based on its ability to temporarily persist in plants, the insect intestine and in the intestinal tract of vertebrate animals, it was designated as a nomadic organism. L. plantarum is Gram positive, bacilli shaped bacterium. L. plantarum cells are rods with rounded ends, straight, generally 0.9–1.2 μm wide and 3–8 μm long, occurring singly, in pairs or in short chains. L. plantarum has one of the largest genomes known among the lactic acid bacteria and is a very flexible and versatile species. It is estimated to grow between pH 3.4 and 8.8. Lactiplantibacillus plantarum can grow in the temperature range 12 °C to 40 °C. The viable counts of the "L. plantarum" stored at refrigerated condition (4 °C) remained high, while a considerable reduction in the counts was observed stored at room temperature.
Heyndrickxia coagulans is a lactic acid–forming bacterial species. This species was transferred to Weizmannia in 2020, then to Heyndrickxia in 2023.
Lacticaseibacillus casei is an organism that belongs to the largest genus in the family Lactobacillaceae, a lactic acid bacteria (LAB), that was previously classified as Lactobacillus casei. This bacteria has been identified as facultatively anaerobic or microaerophilic, acid-tolerant, non-spore-forming bacteria.
Lacticaseibacillus 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 also includes L. paracasei and L. zeae. It is a short Gram-positive homofermentative facultative anaerobic non-spore-forming rod that often appears in chains. Some strains of L. rhamnosus bacteria are being used as probiotics, and are particularly useful in treating infections of the female urogenital tract, most particularly very difficult to treat cases of bacterial vaginosis. The species Lacticaseibacillus rhamnosus and Limosilactobacillus reuteri are commonly found in the healthy female genito-urinary tract and are helpful to regain control of dysbiotic bacterial overgrowth during an active infection. L. rhamnosus sometimes is used in dairy products such as fermented milk and as non-starter-lactic acid bacterium (NSLAB) in long-ripened cheese. While frequently considered a beneficial organism, L. rhamnosus may not be as beneficial to certain subsets of the population; in rare circumstances, especially those primarily involving weakened immune system or infants, it may cause endocarditis. Despite the rare infections caused by L. rhamnosus, the species is included in the list of bacterial species with qualified presumed safety (QPS) status of the European Food Safety Agency.
Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation, giving them the common name lactic acid bacteria (LAB).
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.
The Lactobacillaceae are a family of lactic acid bacteria. It is the only family in the lactic acid bacteria which includes homofermentative and heterofermentative organisms; in the Lactobacillaceae, the pathway used for hexose fermentation is a genus-specific trait. Lactobacillaceae include the homofermentative lactobacilli Lactobacillus, Holzapfelia, Amylolactobacillus, Bombilactobacillus, Companilactobacillus, Lapidilactobacillus, Agrilactobacillus, Schleiferilactobacillus, Loigolactobacillus, Lacticaseibacillus, Latilactobacillus, Dellaglioa, Liquorilactobacillus, Ligilactobacillus, and Lactiplantibacillus; the heterofermentative lactobacilli Furfurilactobacillus, Paucilactobacillus, Limosilactobacillus, Fructilactobacillus, Acetilactobacillus, Apilactobacillus, Levilactobacillus, Secundilactobacillus, and Lentilactobacillus, which were previously classified in the genus Lactobacillus; and the heterofermentative genera Convivina, Fructobacillus, Leuconostoc, Oenococcus, and Weissella which were previously classified in the Leuconostocaceae.
Streptococcus thermophilus formerly known as Streptococcus salivarius subsp. thermophilus is a gram-positive bacterium, and a fermentative facultative anaerobe, of the viridans group. It tests negative for cytochrome, oxidase, and catalase, and positive for alpha-hemolytic activity. It is non-motile and does not form endospores. S. thermophilus is fimbriated.
Limosilactobacillus fermentum is a Gram-positive species in the heterofermentative genus Limosilactobacillus. It is associated with active dental caries lesions. It is also commonly found in fermenting animal and plant material including sourdough and cocoa fermentation. A few strains are considered probiotic or "friendly" bacteria in animals and at least one strain has been applied to treat urogenital infections in women. Some strains of lactobacilli formerly mistakenly classified as L. fermentum have since been reclassified as Limosilactobacillus reuteri. Commercialized strains of L. fermentum used as probiotics include PCC, ME-3 and CECT5716
Latilactobacillus sakei is the type species of the genus Latilactobacillus that was previously classified in the genus Lactobacillus. It is homofermentative; hexoses are metabolized via glycolysis to lactic acid as main metabolite; pentoses are fermented via the Phosphoketolase pathway to lactic and acetic acids.
Microbial food cultures are live bacteria, yeasts or moulds used in food production. Microbial food cultures carry out the fermentation process in foodstuffs. Used by humans since the Neolithic period fermentation helps to preserve perishable foods and to improve their nutritional and organoleptic qualities. As of 1995, fermented food represented between one quarter and one third of food consumed in Central Europe. More than 260 different species of microbial food culture are identified and described for their beneficial use in fermented food products globally, showing the importance of their use.
Lactiplantibacillus paraplantarum is a rod-shaped species of lactic acid bacteria first isolated from beer and human faeces. It is facultatively heterofermentative. Strain CNRZ 1885 is the type strain.
Lacticaseibacillus paracasei (commonly abbreviated as Lc. paracasei) is a gram-positive, homofermentative species of lactic acid bacteria that are commonly used in dairy product fermentation and as probiotic cultures. Lc. paracasei is a bacterium that operates by commensalism. It is commonly found in many human habitats such as human intestinal tracts and mouths as well as sewages, silages, and previously mentioned dairy products. The name includes morphology, a rod-shaped bacterium with a width of 2.0 to 4.0μm and length of 0.8 to 1.0μm.
Limosilactobacillus pontis is a rod-shaped, Gram-positive facultatively anaerobic bacterium. Along with other Lactobacillus species, it is capable of converting sugars, such as lactose, into lactic acid. Limosilactobacillus pontis is classified under the phylum Bacillota, class Bacilli, and is a member of the family Lactobacillaceae and is found to be responsible for the fermentation of sourdough, along with many other Lactobacillus species. This microorganism produces lactic acid during the process of fermentation, which gives sourdough bread its characteristic sour taste.
Lactobacillus delbrueckii subsp. bulgaricus is a bacterial subspecies traditionally isolated from European yogurts. Lactobacillus bulgaricusGLB44 differs from other L. bulgaricus strains, because it was isolated from the leaves of Galanthus nivalis in Bulgaria.
Lacticaseibacillus manihotivorans is a starch-hydrolysing lactic acid bacterium first isolated during Cassava sour starch fermentation. It is Gram-positive, catalase-negative, non-spore-forming, non-motile rod-shaped and homofermentative, with type strain OND 32T.
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. Its genome has been sequenced. Lactobaccillus kefiranofaciens was first identified in 1967 in Russia through studying kefir granules. Lactobaccillus kefiranofaciens is part of the Lactobacillus genus and Firmicutes phylum of bacteria. These bacterium metabolize carbohydrates and produce lactic acid, which can be useful in fermentation. Two subspecies have been identified as kefirgranum and kefiranofaciens, which share properties such as being gram-positive, facultatively anaerobic, and rod-shaped.L. kefiranofaciens is the subspecies related to kefir granules. Studies have investigated the origins and causes for variation in kefir composition and led to conflicting results. Some studies indicate the presence of L.kefiranofaciens was due to geographical location, while others indicate it was due to the different milks used.
