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[i]Streptococcus thermopilus[/i] biofilm lifestyle : A remnant of commensal ancestral life?

Abstract : Microorganisms have a long history of use in food production and preservation. Their adaptation to food environments has profoundly modified their features, mainly through genomic flux. Streptococcus thermophilus, one of the most frequent starter culture organisms consumed daily by humans emerged recently from a commensal ancestor. As such, it is a useful model for genomic studies of bacterial domestication processes. Many streptococcal species form biofilms, a key feature of the major lifestyle of these bacteria in nature. However, few descriptions of S. thermophilus biofilms have been reported. An analysis of the ability of a representative collection of natural isolates to form biofilms revealed that S. thermophilus was a poor biofilm producer and that this characteristic was associated with an inability to attach firmly to surfaces. The identification of three biofilm-associated genes in the strain producing the most biofilms shed light on the reasons for the rarity of this trait in this species. These genes encode proteins involved in crucial stages of biofilm formation and are heterogeneously distributed between strains. One of the biofilm genes appears to have been acquired by horizontal transfer. The other two are located in loci presenting features of reductive evolution, and are absent from most of the strains analyzed. Their orthologs in commensal bacteria are involved in adhesion to host cells, suggesting that they are remnants of ancestral functions. The biofilm phenotype appears to be a commensal trait that has been lost during the genetic domestication of S. thermophilus, consistent with its adaptation to the milk environment and the selection of starter strains for dairy fermentations.
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Déposant : Archive Ouverte Prodinra <>
Soumis le : jeudi 1 septembre 2016 - 20:24:51
Dernière modification le : lundi 21 septembre 2020 - 09:40:04


  • HAL Id : hal-01359145, version 1
  • PRODINRA : 369404



Benoit Couvigny, Claire Therial, Celine Gautier, Pierre Renault, Romain Briandet, et al.. [i]Streptococcus thermopilus[/i] biofilm lifestyle : A remnant of commensal ancestral life?. 7th international conference on Gram-positive microorganisms, Jun 2013, Montecatini, Italy. 2013. ⟨hal-01359145⟩



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