Anna Germann

Understanding resource allocation at the cellular level of photosynthetic microconsortia

The efficient allocation of limited resources is a principle strategy for evolutionary success. Since most organisms live in consortia in their natural habitats, the optimal allocation of resources is not only affected by the metabolism of one organism and the medium, but also the metabolic cross-feeding between different organisms. Especially photosynthetic organisms additionally cope with regularly changing constraints, having plenty of energy but sometime limited nutrients available during the day, and the need for allocation of stored carbon and energy reserves for maintenance processes in the night.
The goal of this project is to get a deeper understanding how resources are allocated between different biological processes, different organisms and in a temporal fashion, to cope with changing constraints. At the moment mostly optimality priprinciples are applied, assuming that organisms evolve towards an optimal efficiency. How exactly the optimality conditions can be quantified and measured remained unclear, however. Processes summarized as ‘non-growth-related maintenance’ are less characterized and little theoretical understanding exists that might explain for example upper or lower bounds of the involved processes. 
I plan to investigate resource allocation in a microconsortium of a photosynthetic and a non photosynthetic organism, employing a combined experimental and theoretical approach. The cyanobacterium Synechocystis sp. and the yeast Saccharomyces cerevisiae will be used as model systems to derive a quantitative description of cellular processes. 

Starting date: 01.07. 2019 / Doctoral Researcher

Thesis committee members: Ilka Axmann, Oliver Ebenhöh, Danny Ducat (MSU)

Publications:

Behle A, Saake P, Germann AT, Dienst D, Axmann IM (2020) Comparative dose-response analysis of inducible promoters in cyanobacteria. ACS Synth. Biol. doi:10.1021/acssynbio.9b00505