Lactococcus lactis ssp. lactis gnn.tigr.org/sequenced_genomes/ genome_guide_p2.shtml
Lactococcus lactis is a lactic acid bacteria (LAB),one of a group of microorganisms whose basic function is to convert carbohydrates into lactic acid. • L. lactis ssp. lactis is one of L. lactis’s two subspecies, and was formerly designated Streptococcus lactis. • In nature, L. lactis is found on plant surfaces, animal skin and hair and in the gastrointestinal tracts of animals. It is inactive on the plant but begins to multiply once it reaches an animal’s gastrointestinal tract. distans.livstek.lth.se:2080/ microscopy/foods&bact.htm Streptococcus lactis
For other purposes, L. lactis is a key component in the dairy industry as a starter in cheese fermentation. It is also used to prepare beer, wine, and pickled vegetables. • L. lactis ssp. lactis is the preferred starter for soft cheeses. • It is estimated 10 million tons of cheese are made each year and people consume more than 10^18 of these bacteria. http://cheesenet.wgx.com/
L. lactis subsp. lactis was completely sequenced by Sep.19, 2001 by the Microbial Genetics group at the Institut National de la Recherche Agronomique (INRA) in Jouy en Josas, France and Genoscope, the French National Sequencing Center in Evry, France. www.cheesefesta.com/ • The sequencing strategy employed consisted of two steps: diagnostic genome sequencing and shotgun polishing. In the first part, short genome fragments were cloned using E. coli vectors and sequenced those chosen at random. Multiplex long accurate PCR was used to connect them. The second part was comprised of sequencing more of these clones and followed with primer walking on PCR-generated templates.
Since LAB are comprised of both helpful bacteria, like L. lactis, and pathogenic bacteria, like Streptococcus pneumoniae, having the genome sequenced for at least one LAB is useful. molgen.biol.rug.nl/molgen/research/ lactis/lactis.php Lactococcus lactis cell • Having sequenced the genome, scientists have access to more information about bacteria, vaccines could be made and possible ways that it could improve fermentation methods or find cures for diseases.
Some new findings that came about as a result of • sequencing L.lactis subsp. lactis: • 12 enzymes called aminotransferases that are used to break down amino acids; could lead to more control over flavor of cheese • 29 genes required to build mesh-like cell wall; could be useful in speeding up cheese ripening time • Shown that during production of recombinant proteins, lactococcal strains do not produce endotoxins echo.med.utoronto.ca/ gallery.htm Enzyme Iia From The Lactose Specific Pts From Lactococcus Lactis
L. lactis has 2,310 predicted genes with 64.2% having known roles in cell function, 20.1% matching other hypothetical genes, and 15.7% being unique to this bacterium. • L. lactis has 2,365,589 base pairs and makes up one chromosome. • L. lactis has a G+C content of 35.4%. spock.jouy.inra.fr/wel1.html