Unveiling core ecological interactions in marine microbial communities using omics approaches.

INTERACTOMICS aims at building and analyzing a network of marine microbial interactions using multiple state-of-the-art technologies as well as pre-existing genomic databases from large oceanographic expeditions.

Our knowledge of microbial interaction networks is rudimentary, and in most community studies, microbes are still pooled by their function, thus missing their species-specific interactions. This represents a major knowledge gap, as microbes are key players in almost all ecosystems, particularly in the oceans, and without comprehending their interactions we cannot increase our understanding of the functioning of the biosphere, which is particularly needed in a context of global change. The reason for the current state-of-affairs is that understanding microbial interactions (and diversity) has proven to be highly challenging.

However, recent technological advance in Single Cell Genomics, High-Throughput sequencing, and High-Performance computing makes now feasible to capture the most important microbes of a given community and determine their ecological interactions. Therefore, in this project we propose to focus in a model marine microbial community aiming to:

1. predict important ecological interactions using association networks,
2. test whether predicted interactions exist, determining interaction type (e.g. symbiosis, predation, parasitism) using Single Cell Genomics
3. test if other predicted interactions can be considered as metabolic cooperation using metagenomics and metatranscriptomics an
4. determine the ubiquity of selected significant interactions in the global ocean using existing molecular data from large marine expeditions (Malaspina and Tara Oceans).

Lastly, the main results of this project will be:

1. identification of the most important ecological interactions within the studied microbial community in a temporal context,
2. determination of core metabolic interactions,
3. assembly of a comprehensive interaction network for this model marine site, analyzing its main characteristics and
4. identification of the ubiquity of core microbial interactions in the global ocean.

Overall, the knowledge produced by this project will move forward the research frontier in microbial ecology by determining pairwise species-specific ecological interactions that are the basis of ecosystem functioning.