Ocean microbes develop not only in the free-living state but they also thrive on living organisms and on organic and inorganic substrates. When they do so on sinking organic particles, they are key in the so-called biological carbon pump, regulating the rate of particle decomposition and sinking. Recent research done at the ICM has shown that some groups of microbes prefer to develop on particles, to the point that a strong phylogenetic signal can be observed in particle microbes, that they harbor differential sets of genes, and that particles are colonized in the surface ocean, functioning as vectors of diversity into the deep sea. Particles, in turn, feed a relevant part of the deep ocean metabolism although other mechanisms exist for deep ocean microbes to grow and reproduce. I will review what we know about the particle microbiome, highlighting our research on ocean particles and their microbiomes, research done within projects Malaspina, Blanes Bay and beyond and I will also elaborate some of the hypotheses that derive from these results and that form the basis of the recently started projects Micolor and Pre-Pap, to gather knowledge on ocean particle microbiome dynamics and their relationships to ocean particle flux and carbon sequestration.
I’m a Research Professor at the ICM. My research focuses on the factors that determine the abundance of microorganisms in plankton and their activity, as well as the effects of that activity on the ecosystem. I consider myself a microbial ecologist with a special interest in biogeochemistry (which is the result of microbial activity) and oceanography (as the framework in which microbial activity occurs). Prokaryotes are the main focus of my activity and consequently I have been interested in how predation and the availability of resources regulate their abundance, use of dissolved organic carbon, and how the composition of the microbial black box is regulated in terms of size structure, metabolic characteristics of the community, community structure or composition in genes. I work with empirical analysis of databases, generated mainly in cruises; mesocosm and microcosm experiments, and in the combined use of image analysis and flow cytometry with fluorescent and metabolic probes. On top of research papers and outreach books, I have coedited the last edition of the textbook Microbial Ecology of the Ocean (Wiley, 2018). I believe my work has been somehow useful at postulating and developing highly used tools and concepts that are now considered reference in the field of aquatic microbial ecology and biogeochemical oceanography. I also love to play Satanàs in the Pastorets (;-).