Introduction:
Oxygenic photosynthesis, originating in cyanobacteria, is a critical biological process that drives primary production in most ecosystems. While we understand cyanobacterial growth dynamics in axenic laboratory cultures, most microorganisms evolved in interconnected ecosystems, and understanding their physiology requires taking their evolution within these dynamic ecosystems into account.
Goals:
Our objective is to understand the emergence of interactions between photo- and heterotrophic microorganisms using computational models grounded in biochemical resource allocation analysis. We aim to delineate the prerequisites and energetic trade-offs governing cooperation, division of labor, and nutrient cycles in microbial communities.
Materials & Methods:
Building on previous advancements, we make use of high-quality quantitative computational models of microbial growth and resource allocation. Specifically, we simulate co-cultures of photo- and heterotrophic organisms, where each microbial partner maximizes its growth rate, allowing us to explore whether interactions and dependencies emerge.
Results:
Using a novel computational framework, we simulate interactions between photo- and heterotrophic microorganisms. By examining the costs and benefits of these interactions, we outline a plausible evolutionary pathway for the emergence of metabolic dependencies between these microorganisms in marine environments. We show that co-cultures can result in long-term stable cultures with increased productivity compared to axenic growth.
Summary:
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.