Transcript Lactococcus lactis

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.
distans.livstek.lth.se:2080/ microscopy/foods&bact.htm
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.
 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.
http://cheesenet.wgx.com/
 It is estimated 10 million tons of
cheese are made each year and
people consume more than 10^18 of
these bacteria.
• 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