Lactic acid is an organic acid. It has a molecular formula CH3CH(OH)COOH. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a hydroxyl group adjacent to the carboxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate. The name of the derived acyl group is lactoyl.
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.
Lactobacillus bulgaricus is one of over 200 published species in the Lactobacillus genome complex (LGC) and is the main bacterium used for the production of yogurt. It also plays a crucial role in the ripening of some cheeses, as well as in other processes involving naturally fermented products. It is defined as homofermentive lactic acid bacteria due to lactic acid being the single end product of its carbohydrate digestion. It is also considered a probiotic.
Lactococcus is a genus of lactic acid bacteria that were formerly included in the genus Streptococcus Group N1. They are known as homofermenters meaning that they produce a single product, lactic acid in this case, as the major or only product of glucose fermentation. Their homofermentative character can be altered by adjusting environmental conditions such as pH, glucose concentration, and nutrient limitation. They are gram-positive, catalase-negative, non-motile cocci that are found singly, in pairs, or in chains. The genus contains strains known to grow at or below 7˚C.
Lactococcus lactis is a gram-positive bacterium used extensively in the production of buttermilk and cheese, but has also become famous as the first genetically modified organism to be used alive for the treatment of human disease. L. lactis cells are cocci that group in pairs and short chains, and, depending on growth conditions, appear ovoid with a typical length of 0.5 - 1.5 µm. L. lactis does not produce spores (nonsporulating) and are not motile (nonmotile). They have a homofermentative metabolism, meaning they produce lactic acid from sugars. They've also been reported to produce exclusive L-(+)-lactic acid. However, reported D-(−)-lactic acid can be produced when cultured at low pH. The capability to produce lactic acid is one of the reasons why L. lactis is one of the most important microorganisms in the dairy industry. Based on its history in food fermentation, L. lactis has generally recognized as safe (GRAS) status, with few case reports of it being an opportunistic pathogen.
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, but there is little evidence for many of the health benefits claimed for them.
Leuconostoc is a genus of gram-positive bacteria, placed within the family of Lactobacillaceae. They are generally ovoid cocci often forming chains. Leuconostoc spp. are intrinsically resistant to vancomycin and are catalase-negative. All species within this genus are heterofermentative and are able to produce dextran from sucrose. They are generally slime-forming.
Bifidobacterium animalis is a gram-positive, anaerobic, rod-shaped bacterium of the Bifidobacterium genus which can be found in the large intestines of most mammals, including humans.
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).
Torulaspora delbrueckii is a ubiquitous yeast species with both wild and anthropic habitats. The type strain of T. delbrueckii is CBS 1146T, equivalent to CLIB 230 or ATCC 10662, etc.. The type strain of T. delbrueckii CBS 1146 T was sequenced in 2009, and is composed of 8 chromosomes in addition to a mitochondrial genome.
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.
Matzoon or matsoni is a fermented milk product of Armenian origin, distributed in Armenia and Georgia. The so-called Caspian Sea yogurt circulated and commercialized in Japan is sometimes said to be the same type of yogurt as matzoon, but a comparison of microbiota and viscosity found that the two are entirely different.
Cronobacter is a genus of Gram-negative, facultatively anaerobic, oxidase-negative, catalase-positive, rod-shaped bacteria of the family Enterobacteriaceae. Several Cronobacter species are desiccation resistant and persistent in dry products such as powdered infant formula. They are generally motile, reduce nitrate, use citrate, hydrolyze esculin and arginine, and are positive for L-ornithine decarboxylation. Acid is produced from D-glucose, D-sucrose, D-raffinose, D-melibiose, D-cellobiose, D-mannitol, D-mannose, L-rhamnose, L-arabinose, D-trehalose, galacturonate and D-maltose. Cronobacter spp. are also generally positive for acetoin production and negative for the methyl red test, indicating 2,3-butanediol rather than mixed acid fermentation. The type species of the genus Cronobacter is Cronobacter sakazakii comb. nov.
Kefir ; is a fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic symbiotic culture. It is prepared by inoculating the milk of cows, goats, or sheep with kefir grains.
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.
Lactobacillus delbrueckii subsp. bulgaricus is a bacterial subspecies traditionally isolated from European yogurts. Lactobacillus bulgaricusGLB44 differs from the rest of the L. bulgaricus strains because it was isolated from the leaves of Galanthus nivalis in Bulgaria.
Lactobacillus delbrueckii subsp. lactis is a subspecies of Lactobacillus delbrueckii that is generally used to measure the amount of cobalamin in food. Its growth rate is proportional to the amount of cobalamin in the growth medium. However, lactis has been demonstrated to have the option to utilize pseudocobalamin, which is inactive for humans, as well as "alkali-resistant factors", leading to an overestimation of the amount of cobalamine in food. As such, new methods using HPTLC or LC-MS/MS have also been developed.
Curd, also mosaru or dahi or Thayir or Perugu, is a traditional yogurt or fermented milk product, originating from and popular throughout the Indian subcontinent, usually prepared from cow's milk, and sometimes buffalo milk, or goat milk. The word curd is used in Indian English to refer to homemade yogurt, while the term yogurt refers to the pasteurized commercial variety known as heat treated fermented milk.
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 fermentation of glucose. The species of bacteria is located primarily in guts of mammals and insects.
Postbiotics - also known as metabiotics, biogenics, or simply metabolites - are soluble factors, secreted by live bacteria, or released after bacterial lysis providing physiological benefits to the host.
