Evolution and biogeography of the brackish microbiome

In all aquatic environments, microorganisms are the engines that drive the fluxes of energy and nutrients and form the base of the food web. Due to climate change, temperature and salinity will change in many water bodies.

To predict how ecosystems will change, knowledge on adaptation and redistribution of microbes in response to altered environment conditions is central.

The young (8000yr.) Baltic Sea with its strong environmental gradients is a perfect system for studying microbial colonisation and adaptation. A large body of research has investigated how macro-organisms have adapted to the brackish conditions of this sea. However, little is known about how microorganisms colonised and adapted to this ecosystem.

This project will shed light on the evolutionary history and biogeography of brackish-water prokaryotes by leveraging on a comprehensive catalogue of metagenome-assembled genomes (MAGs) from globally distributed freshwater, brackish and marine environments.

Phylogenomic and population genomic approaches will be combined with analysis of ancient DNA in sediments and DNA from air filters.

The project will shed light on how brackish prokaryotes evolved from their freshwater and marine ancestors, how they differentiate within and disperse between ecosystems, and how the Baltic Sea microbiome has developed over geological time.

Using the brackish microbiome as a model, it will provide insights on how microbial populations evolve, differentiate and disperse in nature.