Unravelling the molecular basis of metabolic interactions in synthetic consortia dedicated for bio-H2 production

Nowadays, it is well established that microbes live in the form of complex communities that sense their environment, communicate between members, and exchange biological materials. This microbial cooperation often allows new function or better performance of the whole community not predictable via genome analysis. Understanding the metabolic interdependence in microbial communities becomes an important challenge to decipher the microbial behavior at the community scale, but also to unlock alternative pathways as for the biotechnological use. Based on the model of microbial biomass degradation which in Nature involved various anaerobic bacteria working in syntrophy, previous research in the group led to the construction of simplified models composed of Desulfovibrio vulgaris and Clostridium acetobutylicum. Under nutritional stress, cell-to-cell interactions were shown to occur allowing nutrients cross-feeding between bacteria. These interactions are essential for D. vulgaris survival. Interestingly, this also led to increase bio-hydrogen production. The establishment of the physical interactions is crucial and depends on the AI-2 quorum sensing (QS) molecules produced by C. acetobutylicum. As nothing was known regarding QS-pathways in these organisms. I am now seeking to decipher the mechanism of interspecies communication by i) identify the QS actors in the 2 bacteria using bioinformatics approaches; ii) identify QS-controlled genes in D. vulgaris and iii) identify the mechanisms involved in the bacterial interaction.