Get Lactococcus Lactis essential facts below. View Videos or join the Lactococcus Lactis discussion. Add Lactococcus Lactis to your PopFlock.com topic list for future reference or share this resource on social media.
L. l. cremoris L. l. hordniae L. l. lactis L. l. lactis bv. diacetylactis L. l. tructae
Lactococcus lactis is a Gram-positivebacterium 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 being an opportunistic pathogen.
L. 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 that then separates to form curds, which 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, such as 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 medium milk were either 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 carbon uptake and metabolism.
L. lactis subsp. lactis (formerly Streptococcus lactis) is used in the early stages for the production of many cheeses, including brie, camembert, Cheddar, Colby, Gruyère, Parmesan, and Roquefort. The state Assembly of Wisconsin, also the number one cheese-producing state in the United States, voted in 2010 to name this bacterium as the official state microbe. It would have been the first and only such designation by a state legislature in the nation, however the legislation was not picked up by the Senate. The legislation was introduced in November 2009 as Assembly Bill 556 by Representatives Hebl, Vruwink, Williams, Pasch, Danou, and Fields; it was cosponsored by Senator Taylor. The bill passed the Assembly on May 15, 2010, and was dropped by the Senate on April 28.
The use of L. lactis in dairy factories is not without issues. Bacteriophages specific to L. lactis cause significant economic losses each year by preventing the bacteria from fully metabolizing the milk substrate. Several epidemiologic studies showed the phages mainly responsible for these losses are from the species 936, c2, and P335 (all from the family Siphoviridae).
The feasibility of using Lactic acid bacteria (LAB) as functional protein delivery vectors has been widely investigated.Lactococcus lactis has been demonstrated to be a promising candidate for the delivery of functional proteins because of its noninvasive and nonpathogenic characters. Many different expression systems of L. lactis have been developed and used for heterologous protein expression.
In Shuichi Nakamura's, Yusuke V. Marimoto, and Seishi Kudo's study, they seek to prove that some fermentation produced by L. lactis can hinder motility in pathogenic bacteria. The motilities of Pseudomonas, Vibrio and Leptospira strains were also severely disrupted by lactose utilization by L. lactis.
Using Salmonellaflagellar as the experimental group, Nakamura's team found that a product of lactose fermentation is the cause of motility impairment in Salmonella. It is suggested that the L. lactis supernatant mainly affects Salmonella motility through disturbing flagellar rotation but not through irreversible damage against morphologies and physiologies. Lactose fermentation by L. lactis produces Acetate that reduces the intracellular pH of Salmonella, which in turn slow down the rotation of their flagella. These results highlight the potential use of L. lactis for preventing infections by multiple bacterial species.
The authors propose two possible routes by which IL-10 can reach its therapeutic target. Genetically engineered L. lactis may produce murine IL-10 in the lumen, and the protein may diffuse to responsive cells in the epithelium or the lamina propria. Another route involves L. lactis taken up by M cells[disambiguation needed] because of its bacterial size and shape, and the major part of the effect may be due to recombinant IL-10 production in situ in intestinal lymphoid tissue. Both routes may involve paracellular transport mechanisms that are enhanced in inflammation. After transport, IL-10 may directly down-regulate inflammation. In principle, this method may be useful for intestinal delivery of other protein therapeutics that are unstable or difficult to produce in large quantities and an alternative to the systemic treatment of IBD.
Tumor-suppressor through Tumor metastasis-inhibiting peptide KISS1
Another study, led by Zhang B, created a L. lactis strain that maintains a plasmid containing a tumor metastasis-inhibiting peptide known as KISS1.L. lactis NZ9000 was demonstrated to be a cell factory for the secretion of biologically active KiSS1 protein, exerting inhibition effects on human colorectal cancer HT-29 cells.
KiSS1 secreted from recombinant L. lactis strain effectively downregulated the expression of Matrix metalloproteinases (MMP-9) - a crucial key in the invasion, metastasis, and regulation of the signaling pathways controlling tumor cell growth, survival, invasion, inflammation, and angiogenesis. The reason for this is that KiSS1 expressed in L. lactis activates the MAPK pathway via GPR54 signaling, suppressing NF?B binding to the MMP-9 promoter and thus downregulating MMP-9 expression. This, in turn, reduces the survival rate, inhibits metastasis and induces dormancy of cancer cells.
In addition, it was demonstrated that tumor growth can be inhibited by the LAB strain itself  due to the LAB's ability to produce exopolysaccharides. This study shows that L. lactisNZ9000 can inhibit HT-29 proliferation and induce cell apoptosis by itself. The success of this strain's construction helped to inhibit migration and expansion of cancer cells, showing that the secretion properties of L. lactis of this particular peptide may serve as a new tool for cancer therapy in the future.
^Madigan M, Martinko J (editors). (2005). Brock Biology of Microorganisms (11th ed.). Prentice Hall. ISBN978-0-13-144329-7.
^Braat H, Rottiers P, Hommes DW, Huyghebaert N, Remaut E, Remon JP, van Deventer SJ, Neirynck S, Peppelenbosch MP, Steidler L (2006). "A phase I trial with transgenic bacteria expressing interleukin-10 in Crohn's disease". Clin Gastroenterol Hepatol. 4 (6): 754-759. doi:10.1016/j.cgh.2006.03.028. PMID16716759.
^ROISSART, H. and Luquet F.M. Bactéries lactiques: aspects fondamentaux et technologiques. Uriage, Lorica, France, 1994, vol. 1, p. 605. ISBN2-9507477-0-1
^Åkerberg, C.; Hofvendahl, K.; Zacchi, G.; Hahn-Hä;gerdal, B. (1998). "Modelling the influence of pH, temperature, glucose and lactic acid concentrations on the kinetics of lactic acid production by Lactococcus lactis ssp. Lactis ATCC 19435 in whole-wheat flour". Applied Microbiology and Biotechnology. 49 (6): 682-690. doi:10.1007/s002530051232.
^Wessels S, Axelsson L, Bech Hansen E, De Vuyst L, Laulund S, Lähteenmäki L, Lindgren S, et al. (November 2004). "The lactic acid bacteria, the food chain, and their regulation". Trends in Food Science & Technology. 15 (10): 498-505. doi:10.1016/j.tifs.2004.03.003.
^Facklam RR, Pigott NE, Collins MD. Identification of Lactococcus species from human sources. Proceedings of the XI Lancefield International Symposium on Streptococci and Streptococcal Diseases, Siena, Italy. Stuttgart: Gustav Fischer Verlag; 1990:127
^Mannion PT, Rothburn MM (November 1990). "Diagnosis of bacterial endocarditis caused by Streptococcus lactis and assisted by immunoblotting of serum antibodies". J. Infect. 21 (3): 317-8. doi:10.1016/0163-4453(90)94149-T. PMID2125626.
^Bolotin A, Quinquis B, Renault P, Sorokin A, Ehrlich SD, Kulakauskas S, Lapidus A, et al. (2004). "Complete sequence and comparative genome analysis of the dairy bacterium Streptococcus thermophilus". Nature Biotechnology. 22 (12): 1554-8. doi:10.1038/nbt1034. PMID15543133.
^ abCoffey A, Ross RP (2002). "Bacteriophage-resistance systems in dairy starter strains: molecular analysis to application". Antonie van Leeuwenhoek. 82 (1-4): 303-21. doi:10.1023/A:1020639717181. PMID12369198.
^Benbouziane B, Ribelles P, Aubry C, Martin R, Kharrat P, Riazi A, Langella P, Bermudez-Humaran LG (2013). "Development of a Stress-Inducible Controlled Expression (SICE) system in Lactococcus lactis for the production and delivery of therapeutic molecules at mucosal surfaces". J. Biotechnol. 168 (2): 120-129. doi:10.1016/j.jbiotec.2013.04.019.
^Nakamura S, Morimoto YV, Kudo S (2015). "A lactose fermentation product produced by Lactococcus lactis subsp. lactis, acetate, inhibits the motility of flagellated pathogenic bacteria". Microbiology. 161 (4): 701-707. doi:10.1099/mic.0.000031. PMID25573770.
^Kihara M, Macnab RM (1981). "Cytoplasmic pH mediates pH taxis and weak-acid repellent taxis of bacteria". J Bacteriol. 145: 1209-1221. PMID7009572.
^Repaske DR, Adler J (1981). "Change in intracellular pH of Escherichia coli mediates the chemotactic response to certain attractants and repellents". J Bacteriol. 145: 1196-1208. PMID7009571.
^Stordeur P, Goldman M (1998). "Interleukin-10 as a regulatory cytokine induced by cellular stress: molecular aspects". Int. Rev. Immunol. 16 (5-6): 501-522. doi:10.3109/08830189809043006. PMID9646174.
^Zhang B, Li A, Zuo F, Yu R, Zeng Z, Ma H, Chen S (2016). "Recombinant Lactococcus lactis NZ9000 secretes a bioactive kisspeptin that inhibits proliferation and migration of human colon carcinoma HT-29 cells". Microbial Cell Factories. 15 (1): 102. doi:10.1186/s12934-016-0506-7.
^Bauvois B (2012). "New facets of matrix metalloproteinases MMP-2 and MMP-9 as cell surface transducers: outside-in signaling and relationship to tumor progression". Biochim Biophys Acta. 1825: 29-36. doi:10.1016/j.bbcan.2011.10.001.
^Kessenbrock K, Plaks V, Werb Z (2010). "Matrix metalloproteinases: regulators of the tumor microenvironment". Cell. 141: 52-67. doi:10.1016/j.cell.2010.03.015.
^Klein T, Bischoff R (2011). "Physiology and pathophysiology of matrix metalloproteases". Amino Acids. 41 (2): 271-290. doi:10.1007/s00726-010-0689-x.
^Hirayama K, Rafter J (1999). "The role of lactic acid bacteria in colon cancer prevention: mechanistic considerations". Antonie van Leeuwenhoek. 76: 391-394.
^Ruas-Madiedo P, Hugenholtz J, Zoon P (2002). "An overview of the functionality of exopolysaccharides produced by lactic acid bacteria". Int Dairy J. 12 (2-3): 163-171. doi:10.1016/S0958-6946(01)00160-1.
^Looijesteijn PJ, Trapet L, de Vries E, Abee T, Hugenholtz J (2001). "Physiological function of exopolysaccharides produced by Lactococcus lactis". Int J Food Microbiol. 64 (1-2): 71-80. doi:10.1016/S0168-1605(00)00437-2.
^Ji K, Ye L, Ruge F, Hargest R, Mason MD, Jiang WG (2014). "Implication of metastasis suppressor gene, Kiss-1 and its receptor Kiss-1R in colorectal cancer". BMC Cancer. 14: 1. doi:10.1186/1471-2407-14-723.