The team « Communication Bactérienne » (ComBac) conducts fundamental and applied researches on lactic acid bacteria, especially Streptococcus and Lactococcus. We are interested in understanding their adaptative responses to their various ecosystems including food matrices, intestinal microbiota and host, and how these responses impact their environment using different approaches (microbiology, genetics, biochemistry, genomics and post-genomics, including peptidomics).
Human nutrition is faced to new challenges including food transition to promote a more sustainable food production system. Fermented foods are particularly relevant to meet these challenges, and especially foods of plant origin. In this context, we are investigating the physiology and metabolic activity of the two main lactic acid bacteria traditionally used in dairy fermentation, namely S. thermophilus and L. lactis, in the frame of these plant-based fermentations. We are mainly focusing on the fermentation of legumes, which are nutritionally relevant, particularly in terms of protein richness, and which play a key role in the agro-ecological protein transition.
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Streptococci from the salivarius group are present in all the sections of the human gastrointestinal tract (GIT), such as Streptococcus salivarius, but are also transiently present after consumption of fermented foods such as Streptococcus thermophilus (and also Lactococcus). We are investigating the health beneficial effects of these species (i) at the cellular or molecular scales through their bacterial surface components or the metabolite produced and (ii) in food matrices for food-related species.
The aim of this axis is to decipher the interaction with the host of commensal or food-related streptococci, living in or transiting through human gut.
Team focuses on:
We are working at identifying and characterizing cell-cell communication and regulation systems known as quorum sensing systems in streptococci and lactococci. These systems are based on paired peptides and transcriptional regulators. Team focuses on regulators of the Rgg family and peptides known as SHPs. Deciphering their functional mechanisms makes it possible to conceive new methods to control the functions they exert, such as bacterial competence or antimicrobial production.
Team focuses on:
All the team publications are available in the COMBAC-MICALIS HAL collection
