Auxotrophies in microbial interaction networks – environmental significance and bio-technological applications

Aquatic microorganisms and their complex ecological interactions are responsible for fixing about half of the carbon dioxide on Earth. Among microbial interactions, auxotrophies are important and yet key questions about them remain unanswered. Auxotrophy is defined as the inability to produce an essential metabolite.

As environmental microorganisms evolved, they also developed auxotrophies and dependencies.We will conduct a comprehensive auxotrophy survey using the biggest dataset for oxygen stratified freshwater bodies to date to understand the distribution of auxotrophies in different taxa and the roles these interconnected taxa play in the carbon cycle.

Growth and analysis of aquatic microbial model communities will allow testing the specificity of microbial interactions through auxotrophies and the mode of outsourcing of essential metabolites.

Through selection using genome-wide cyanobacteria mutants followed by metabolic engineering and directed evolution, we will test biotechnological applications of auxotrophies.

The designed synthetic communities will also serve as systematic validation strategy of interactions observed in nature.

This project will push the frontiers of knowledge about aquatic microbial interaction networks and the role of auxotrophies in the microbial trading system.

The results will fine-tune carbon cycle models and will provide tools to biotechnology for a sustainable green bioeconomy.