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Le Laboratoire de Microbiologie et Génétique Moléculaires

UMR 5100



The Laboratoire de Microbiologie et Génétique Moléculaires (LMGM) studies the organization, evolution and expression of the genomes of bacteria and bacteriophage. Our research ranges from the study of single molecules to living bacterial cells and their interaction with the environment. This research is based on approaches that include molecular genetics, biochemistry, genomics and bioinformatics. The bacteria and bacteriophage that we study are model organisms interesting for fundamental research as well as for applications in biotechnology, the food industry and the medical sciences.


Le Laboratoire de Microbiologie et Génétique Moléculaires supports "Sciences en marche"
Sciences en marche

News Archives






  •   Chaperone addiction of toxin-antitoxin systems

    Bacterial toxin-antitoxin (poison-antidote) systems, in which a labile antitoxin binds and inhibits a noxious toxin, can promote adaptation, persistence and multi-drug tolerance by modulating bacterial growth in response to stress. Some atypical toxin-antitoxins, known as tripartite toxin-antitoxin-chaperone (TAC) modules, also include a stress-responsive molecular chaperone that facilitates folding and protects the antitoxin from degradation. Using a TAC module from the major human pathogen Mycobacterium tuberculosis as a model to investigate the molecular mechanisms by which classical TAs can become ‘chaperone-addicted’, researchers form the “Laboratoire de microbiologie et génétique moléculaires, Centre de biologie integrative” and from the “Institut de pharmacologie et de biologie structural” in Toulouse have now identified a short chaperone addiction sequence (ChAD) within TAC antitoxins, to which the chaperone binds and which can be transferred to other proteins to make them chaperone-dependent. This mechanism might be used to optimize the expression and folding of heterologous proteins in bacterial hosts for biotechnological or medical purposes. This work is published in Nature Communications 7, 2016.


    plusPour en savoir plus

  •   Reception of students for the festival of science

    On October 14th, CBI hosted an open day with high-school students. The LBME and the LMGM accommodated scientific senior secondary school students for an original discovery of the world of research. The students could visit the laboratories, discuss with researchers during mini-conferences and take part in many interactive workshops animated by researchers, engineers, technicians, and PhD students of the two laboratories.
    Beautiful human and scientific experiences and experiments.

  •   PhD defense : Léa Marie (Polard Team)

    Functional study of the homologous recombination pathway effectors acting during genetic transformation of Streptococcus pneumoniae pathogen.
    October 21 2016 - 14h00 - IBCG Conference room.

  •   PhD defense : Franck Pasta (Bouet Team)

    From DNA repair in pneumococcus to genome partitioning in the Burkholderiales.
    October 19 2016 - 10h00 - Einstein Amphitheatre, UPS.

  •   PhD defense : Alix Corneloup (Ton-Hoang Team)

    The spread of REP sequences in bacterial genomes, characterising the activities of the TnpAREP proteins.
    October 18 2016 - 14h00 - IBCG Conference room.

  •   PhD defense : Florian Fournes (Cornet Team)

    Study of the Xer system through the horizontal and vertical genetic transmission in bacteria.
    October 03 2016 - 14h00 - IBCG Conference room.

  •   PhD defense : Elise Lebailly (Cornet Team)

    The role of the E. coli. chromosome terminus in positioning, chromosomal segregation, and division control.
    September 30 2016 - 14h00 - IBCG Conference room.

  •   Destabilization of the genome of the bacterium Burkholderia cenocepacia

    Burkholderia cenocepacia, a bacterial pathogen to which sufferers from cystic fibrosis are highly susceptible, has three chromosomes. Dave Lane and Franck Pasta at the LMGM have shown by fluorescence microscopy that transmission of chromosome copies to daughter cells is sequential - the largest first, the smallest last. Each chromosome codes for a mitotic system whose inactivation disrupts the transmission and causes cellular anomalies. This work, published in PLoS Genetics, raises the prospect of targeting these mitotic systems for anti-B.cencepacia treatment.


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  •   A new model for the assembly of the nucleoprotein complex involved in bacterial DNA segregation

    The previous mechanism for assembly of the bacterial DNA segregation apparatus has been challenged by a multi-approach study, and a new molecular mechanism has been proposed. This work, published in Cell Systems, has been performed in the team “bacterial DNA segregation: mechanism and diversity” directed by J.-Y. Bouet at the Laboratory of Molecular Genetics and Microbiology (LMGM, CNRS/University Toulouse III - Paul Sabatier), in collaboration with the teams of M. Nollmann at the Center for Structural Biochemistry (CBS, Montpellier) and A. Parmeggiani at the Laboratory Charles Coulomb (LCC, Montpellier).

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  •   Midcell DNA uptake for pneumococcal transformation

    Genetic transformation, in which cells internalize exogenous DNA and integrate it into their chromosome, is widespread in the bacterial kingdom. Results published in PLoS Pathogens by the team of J.P. Claverys and P. Polard (Laboratoire de microbiologie et de génétique moléculaires, LMGM, CNRS/Université Toulouse III - Paul Sabatier) show that in the human pathogen Streptococcus pneumoniae (the pneumococcus), active uptake of transforming DNA takes place at midcell, in contrast to the polar uptake previously reported for Bacillus subtilis.

  •   Chromosome segregation

    Chromosome segregation is a key step of cell division, allowing production of strictly identical sister cells carrying the whole genetic material from their mother. In bacteria, chromosome segregation is not a random process but occurs in a ordered and oriented manner relying on the activity of several different proteins. This result has been published in PNAS by the team led by F. Cornet in the Laboratoire de microbiologie et génétique moléculaires (LMGM, CNRS/Université Toulouse III - Paul Sabatier).

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  •   DprA, a protein that controls pneumococcal competence

    The bacterium Streptococcus pneumoniae, also known as the pneumococcus, is able to integrate exogenous DNA into its genome. This process of « genetic transformation » requires the induction of a transient physiological state named « competence ». The pivotal role of the DprA protein in the shut-off of competence has just been documented by the 'Pneumococcal Transformation' team of the Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM, CNRS/Université Toulouse III - Paul Sabatier), in collaboration with researchers from the Micalis Institute (INRA, Jouy en Josas). These findings were recently published in PNAS.

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  •   The group directed by Jean-Pierre Claverys and Patrice Polard,

    working on the human pathogen Streptococcus pneumoniae (the pneumococcus), has established that the single-stranded DNA-specific methylase DpnA plays an important role in the genetic transformation of this bacteria. DpnA could be responsible for the genetic variability of half the strains present in nature.

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  •   Mick Chandler's emeritus

    The LMGM is organizing a mini-symposium to celebrate the Emeritus that Mick Chandler will assume upon retirement in August 2013. The meeting will be held Wednesday June 12 and Thursday June 13, 2013 in the conference room of the IBCG. It will include scientific and non-scientific presentations and a buffet lunch on Thursday at the IBCG. To register and for more information, please use our web page before April 15, 2013.

  •   The group directed by P. Genevaux

    Has extensively characterized a novel ORFan-encoded protein, Rki, encoded by the large, virulent enterobacteriaceae bacteriophage RB43. They have shown that Rki functions to control the host stress-response during the early stages of bacteriophage infection, specifically by interacting with the host DnaK/Hsp70 chaperone to stabilize the major host heat-shock factor, ?32.

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    Researchers from the Laboratory of Microbiology and Molecular Genetics (CNRS/Université Paul Sabatier, Toulouse) have recently demonstrated the presence of a short "window of opportunity" in E. coli during which the transposase of the bacterial insertion sequence IS911 is capable of ensuring IS911 movement in the host genome. This mechanism, which is described in an article published on December 23 2011 in Molecular Cell, efficiently regulates transposition by bringing into play an unexpected partner: the ribosome.

    plusPour en savoir plus

  •   The group directed by Jean-Pierre Claverys and Patrice Polard

    have documented the role of the single-stranded DNA binding protein SsbB in the genetic transformation of the pneumococcus, baptised Streptococcus pneumoniae in 1974. This protein could be particularly important for the diversification of the genome of this bacterium. This work was published June 30, 2010 in PLoS Genetics.

    plusPour en savoir plus

  •   The group directed by Pierre Genevaux

    has identified in the bacillus of Koch, responsible for tuberculosis, a new toxin-antitoxin system, the TAC system, controlled by a third actor : the chaperon Rv1957. This work was published May 2, 2011 in PNAS.

    plusPour en savoir plus


New members :


Peter REDDER, Professeur, UPS dans l'quipe REDDER

Manuel CAMPOS, Post-Doctorant dans l'quipe CORNET

Calum JOHNSTON, Chargé de Recherche, CNRS dans l'quipe POLARD

Raffaele IEVA, Chargé de Recherche, CNRS dans l'quipe IEVA

David DE LEMOS, Doctorant dans l'quipe POLARD

Emeline VERNHES, Post-Doctorant dans l'quipe POLARD

Ignacio GONZALEZ, Chargé de Recherche, CNRS dans l'quipe CARPOUSIS

Cecile ALBENNE, Maître de Conférences, UPS dans l'quipe IEVA

Camille PEYRE, Stagiaire dans l'quipe CORNET

Céline PÉLISSIER, Adjoint technique, UPS dans l'quipe REDDER

Gladys MUNOZ, Technicien, CNRS dans l'quipe REDDER

DONNA-JOE BIGOT, Assistant Ingénieur, CNRS dans l'quipe GENEVAUX


: This site hosts the two MultiLocus Sequence Typing (MLST) schemes developed for Lactococcus lactis.

ISFinder: This database provides a list of insertion sequences isolated from eubacteria and archae .


ABCdb : a data base on the ABC transporters



T4-type Phage Genome Website





Seminars Toulouse Microbiology


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Laboratoire de Microbiologie
et Génétique Moléculaires
UMR 5100