The biogeochemical cycling of carbon is central in the modulation of Earth’s global temperature and climate by controlling the amount of carbon dioxide and other greenhouse gases in the atmosphere. Global estimates indicate that photosynthetic microorganism in aquatic environments are responsible for approximately half of the carbon dioxide fixed on Earth. A large part of this primary production is due to the activity of aquatic cyanobacteria that are globally ubiquitous and essentially most abundant photosynthetic organisms on Earth. These microorganisms transform carbon from the atmosphere into more than a thousand different organic compounds that are then released in aquatic environments for heterotrophic bacteria to consume. Despite the central role in the global carbon cycle, many aspects of the cross-talk between cyanobacteria and associated heterotrophs are still poorly understood.

Aquatic microorganisms have coevolved together for millions of years, developing intricate interaction patterns. Some of these interaction patters can be understood under cooperation models that combine the continuum of symbiotic interactions with phylogenetic information of aquatic microorganisms (Mondav et al., 2020)

The ecotype cooperation model describes anabolic variability within species as the main contributor to coexistence while allowing for recombination and swapping of metabolic modules across strains. The community cooperation model also encompasses anabolic complementarity but between different species and includes common goods ranging from expensive to costless. The community detrital model places complementarity both between and within species but describes catabolic variation.

We believe it is key to consider and investigate aquatic microbial interactions in the shape of in auxotrophies, metabolic complementarities, metabolic handoffs, microbial market and any kind of microbial cooperation. Not only do we want to understand nature and its interactions, but we want to grasp the complexity of the microbial processes that move the biogeochemical cycles such as the carbon cycle.

Our research vision is to further our understanding of carbon cycle in aquatic environments by revealing the role of interactions and microbial and molecular diversity. One goal is to obtain a fundamental understanding of the carbon flow from carbon dioxide through cyanobacteria, to the diversity of dissolved organic carbon molecules and the bacterial heterotrophs that consume these organic nutrients. Moreover, we want to use ecological principles to engineer biosystems to mitigate the global carbon balance dilemma.