Systems/Synthetic Biology and Evolutionary Dynamics

Confirmed keynote speakers for this session:

Jose Jimenez (University of Surrey, UK): "Impact of molecular interventions on eco-evo dynamics of experimentally tractable microbial systems":

As a result of natural selection, microorganisms tend to maximise their fitness in any given environmental condition. This leads to a multilevel process of optimisation that produces the microbial strains (and communities) best adapted to the ecological constraints of a particular niche. The predictable manipulation of microbial communities is desirable for a number of applications such as those related to the prevention of pathogenic processes. Our capabilities to modify these communities on demand towards achieving a goal are, however, hindered by the complexity of interactions between the organisms present in these communities as well as by their interactions with their environment. In this talk I will present our recent work on population dynamics of bacterial communities under lab controlled conditions. I will focus on two case scenarios: the influence of factors such as population structure in the transmission of antibiotic resistance genes, and on the engineering of strains of Pseudomas aeruginosa for the invasion of microbial populations exploiting the social biology linked to the siderophore pyoverdine.

Sara Mitri (Université de Lausanne, CH): "Eco-evolutionary dynamics in a synthetic bacterial community":

Eco-evolutionary dynamics are little understood within large microbial communities. Disentangling how microbial species interact with one another and how these interactions co-evolve over time needs to first be carried out on simpler ecosystems. We have focused on a synthetic bacterial community consisting of just four species involved in bioremediation. Using a well-defined medium, the four species grow in a closed system, in which we can closely follow bacterial abundances, the interactions between the four species and their genetic changes, during short- and long-term evolutionary experiment. We first show that the species have positive growth effects on one another and that this depends on growth medium composition. We then ask: what will happen to these positive interactions over time? Over approximately 500 generations, we find that species abundances fluctuate following patterns that differ depending on community composition. Out of five replicate communities containing all four species, three resulted in stable co-existence. We find that positive interactions are maintained in this four-species community, but are lost when species grow alone.