Skip to main content

Lactococcus lactis

 

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.

Lactococcus lactis is of crucial importance for manufacturing dairy products, such as buttermilk and cheeses. When L. lactis ssp. lactis is added to milk, the bacterium uses enzymes to produce energy molecules (ATP), from lactose. The byproduct of ATP energy production is lactic acid. The lactic acid produced by the bacterium curdles the milk, which then separates to form curds that are used to produce cheese. Other uses that have been reported for this bacterium include the production of pickled vegetables, beer or wine, some breads, and other fermented foodstuffs like soymilk kefir, buttermilk, and others. L. lactis is one of the best characterized low GC Gram positive bacteria with detailed knowledge on genetics, metabolism and biodiversity.

L. lactis is mainly isolated from either the dairy environment, or plant material. Dairy isolates are suggested to have evolved from plant isolates through a process in which genes without benefit in the rich milk were lost, or down-regulated. This process, also called genome erosion or reductive evolution is also described in several other lactic acid bacteria. The proposed transition from the plant to the dairy environment was reproduced in the laboratory through experimental evolution of a plant isolate that was cultivated in milk for a prolonged period. Consistent with the results from comparative genomics (see references above) this resulted in L. lactis losing or down-regulating genes which are dispensable in milk and the up-regulation of peptide transport.

Hundreds of novel small RNAs were identified by Meulen et al. in the genome of L. lactis MG1363. One of them: LLnc147, was shown to be involved in carbon uptake and metabolism.


Effects of Heat-Killed Lactococcus lactis Strain Plasma on Skin Homeostasis-Related Genes and the Skin Microbiome among Healthy Adults: A Randomized Controlled Double-Blind Study Toshio Fujii, Takashi Fujitomo, Ryohei Tsuji, Ryuichi Kubo, Yukiko Kato, Osamu Kanauchi Microorganisms. 2021 Oct; 9(10): 2029. Published online 2021 Sep 25. doi: 10.3390/microorganisms9102029 PMCID: PMC8539941
The Effects of Dietary Supplementation of Lactococcus lactis Strain Plasma on Skin Microbiome and Skin Conditions in Healthy Subjects—A Randomized, Double-Blind, Placebo-Controlled Trial Ryohei Tsuji, Kamiyu Yazawa, Takeshi Kokubo, Yuumi Nakamura, Osamu Kanauchi Microorganisms. 2021 Mar; 9(3): 563. Published online 2021 Mar 9. doi: 10.3390/microorganisms9030563 PMCID: PMC8000884
Oral intake of heat-killed cells of Lactococcus lactis strain H61 promotes skin health in women Hiromi Kimoto-Nira, Reiji Aoki, Keisuke Sasaki, Chise Suzuki, Koko Mizumachi J Nutr Sci. 2012; 1: e18. Published online 2012 Dec 6. doi: 10.1017/jns.2012.22 PMCID: PMC4153081
PROBIOTICS - TYPES AND EFFECTS OF LACTIC ACID BACTERIA - AZ Sportivo Performance & AZSP Healing


Popular posts from this blog

Nitric oxide

Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula NO. It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its chemical formula (N=O or NO). Nitric oxide is also a heteronuclear diatomic molecule, a class of molecules whose study spawned early modern theories of chemical bonding. An important intermediate in industrial chemistry, nitric oxide forms in combustion systems and can be generated by lightning in thunderstorms. In mammals, including humans, nitric oxide is a signaling molecule in many physiological and pathological processes. It was proclaimed the "Molecule of the Year" in 1992. The 1998 Nobel Prize in Physiology or Medicine was awarded for discovering nitric oxide's role as a cardiovascular signalling molecule. Nitric oxide should not be confused with nitrogen dioxide (NO2), a brown gas and major air pollutant, nor with...

Peptide YY

Peptide YY (PYY) also known as peptide tyrosine tyrosine is a peptide that in humans is encoded by the PYY gene. Peptide YY is a short (36-amino acid) peptide released from cells in the ileum and colon in response to feeding. In the blood, gut, and other elements of periphery, PYY acts to reduce appetite; similarly, when injected directly into the central nervous system, PYY is also anorexigenic, i.e., it reduces appetite. Dietary fibers from fruits, vegetables, and whole grains, consumed, increase the speed of transit of intestinal chyme into the ileum, to raise PYY3-36, and induce satiety. Peptide YY cannot be produced as the result of enzymatic breakdown of crude fish proteins and ingested as a food product; this was a previous attempt to falsify the record of this page.

Limosilactobacillus

  Limosilactobacillus is a thermophilic and heterofermentative genus of lactic acid bacteria created in 2020 by splitting from Lactobacillus. The name is derived from the Latin limosus "slimy", referring to the property of most strains in the genus to produce exopolysaccharides from sucrose. The genus currently includes 31 species or subspecies, most of these were isolated from the intestinal tract of humans or animals. Limosilactobacillus reuteri has been used as a model organism to evaluate the host-adaptation of lactobacilli to the human and animal intestine and for the recruitment of intestinal lactobacilli for food fermentations. Limosilactobacilli are heterofermentative and produce lactate, CO2, and acetate or ethanol from glucose; several limosilactobacilli, particularly strains of Lm. reuteri convert glycerol or 1,2-propanediol to 1,3 propanediol or propanol, respectively. Most strains do not grow in presence of oxygen, or in de Man, Rogosa Sharpe (MRS) mediu...

infrahyoid muscles

The infrahyoid muscles , or strap muscles , are a group of four pairs of muscles in the anterior (frontal) part of the neck. The four infrahyoid muscles are the sternohyoid , sternothyroid , thyrohyoid and omohyoid muscles. Excluding the sternothyroid, the infrahyoid muscles either originate from or insert on to the hyoid bone. The term infrahyoid refers to the region below the hyoid bone, while the term strap muscles refers to the long and flat muscle shapes which resembles a strap. The stylopharyngeus muscle is considered by many to be one of the strap muscles, but is not an infrahyoid muscle.

Sauna

Related Articles reference 1: Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men Antti Mero, Jaakko Tornberg, Mari Mäntykoski, Risto Puurtinen Springerplus. 2015; 4: 321. Published online 2015 Jul 7. doi: 10.1186/s40064-015-1093-5 PMCID: PMC4493260 2: Prophylactic Effects of Sauna on Delayed-Onset Muscle Soreness of the Wrist Extensors Peanchai Khamwong, Aatit Paungmali, Ubon Pirunsan, Leonard Joseph Asian J Sports Med. 2015 Jun; 6(2): e25549. Published online 2015 Jun 20. doi: 10.5812/asjsm.6(2)2015.25549 PMCID: PMC4592767 3: Sauna Yoga Superiorly Improves Flexibility, Strength, and Balance: A Two-Armed Randomized Controlled Trial in Healthy Older Adults Heidi Bucht, Lars Donath Int J Environ Res Public Health. 2019 Oct; 16(19): 3721. Published online 2019 Oct 2. doi: 10.3390/ijerph16193721 PMCID: PMC6801954 4: Steam sauna and mother roasting in Lao PDR: practices and chemical constituents of ess...