Carbon acquisition is pivotal to microbial communities. Hence, individual members exhibit different strategies for carbon uptake, logistics and metabolisation. Here, we will establish a synthetic lichen-like microbial consortium composed of a cyanobacterium and two fungi. We will address different economic strategies of sucrose production, secretion, uptake and metabolisation as a test case for carbon management in microbial communities. Iterative cycles of computational modelling and experimental approaches, modulating the individual strategies of the different members, will guide our project to derive significant, novel insights into the regulation of stable communities.

^{Carbon economics in the envisioned synthetic cross-kingdom consortium. Synechocystis is the carbon producer in the photoautotrophic module driven by sunlight and CO2, while U. maydis and S. cerevisiae compete for carbon in the heterotrophic modules. Sucrose as a common good can be digested extracellularly by periplasmic invertases (red) or internalised by membrane transporters for intracellular hydrolysis by cytosolic invertases (orange). In this project, different carbon utilisation scenarios will be engineered (private, public, cheater). Tuning and switching of the sucrose metabolism will be implemented and the consequences will be analysed via intracellular biosensors.}