PhD: Development, characterization and control of E.coli communities on an automated experimental platform - Maaike Sangster

The study of microorganisms in communities is important for the understanding of their metabolism and their association with human disease, but also for a range of biotechnological applications, since microbial consortia can be used to increase the production of relevant compounds. Our group previously developed a coarse-grained mathematical model of a promising consortium. In this PhD project, we construct this consortium of two E.coli strains, a glucose specialist and an acetate specialist, with the aim of improving our quantitative understanding of the conditions for co-existence and the possible accompanying trade-offs. To study the growth of this consortium, we use an automated experimental platform that we developed in-house, which allows us to vary and measure the growth conditions dynamically. We show that the growth of the individual strains can be explained well with the existing mathematical model. However, our results also suggest that acetate cycling should be modeled in more detail in order to explain the growth of the consortium at low growth rates where co-existence occurs. With this study, we provide insight into the community dynamics and emergent properties of a prototypical synthetic microbial consortium. It highlights the importance of studying co-cultures as opposed to mono-cultures and provides an improved understanding of overflow metabolism in E.coli.

Membres du jury: Fabien Létisse, Steffen Klamt, Madalena Chaves, Franz Bruckert

Direction de thèse: Eugenio Cinquemani and Hans Geiselmann