Eating the Sun: the path from single cell growth to productive ecosystems

• Applicant: Dr. Ralf Steuer
• Subject Area: Bioinformatics and Theoretical Biology ; Microbial Ecology and Applied Microbiology ; Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 453048493

The purpose of this proposal is to establish a new perspective on microbial phototroph-heterotroph interactions using quantitative computational models of microbial resource allocation. While the genomic revolution and the advent of systems biology have brought a wealth of information about microbial growth in axenic cultures, the organization and dynamics of microbial ecosystems are still insufficiently understood. In particular, a number of recent landmark studies have challenged the way we think about phototroph-heterotroph interactions in marine ecosystems. Rather than being mere assemblages of discrete organisms that interact haphazardly, many marine microbial communities are characterized by a high degree of cooperation. The challenge before us is therefore to understand how marine microbes interact and collaborate: what are the pre-requisites and energetic trade-offs for cooperation and division of labor? How do metabolic diversity and mutualistic relationships emerge? To tackle these challenging questions, we will develop a computational framework that allows us to understand the transition from single cell growth to phototroph-heterotroph dependencies. The proposal directly builds upon the high quality quantitative models of microbial resource allocation developed over the past decade. Our premise is that the perspective of cellular resource allocation offers a unique opportunity to understand the constraints and energetic trade-offs that govern the emergence of dependencies between photo- and heterotrophic microorganisms in marine environments. Within the project, we will also address the question whether the emergence of microbial dependencies is accompanied by an increased productivity of ecosystems, as recently suggested by several authors. The proposal is motivated by the importance of microbial cooperation for biospheric processes and our need to understand and manage the future states of our planet.

• DFG Programme: Research Grants