It takes two to tango without oxygen: metabolic syntrophy in eukaryotic evolution

In my PhD project I am investigating symbiosis performed through metabolic interaction between partners (syntrophy) as a driving force in eukaryotic evolution. In the microbial world, symbiotic interactions based on syntrophy where nutrients are exchanged between organisms to allow for metabolic division of labour are common between prokaryotes in anoxic environments and are essential drivers of vital biogeochemical processes like global carbon, nitrogen and sulphur cycling. Whether similar roles can be attributed to protists (single-cell eukaryotes) occupying these environments remains unclear owing in large part to our limited understanding of the biology, syntrophic potential, and metabolism of anaerobic eukaryotes. The overarching aim of this thesis is to discover the diversity and molecular mechanisms underpinning syntrophic interactions in eukaryotes.

The specific objectives are to survey sequencing datasets to predict metabolic pathways of anaerobic eukaryotes, dissect the nature and resilience of syntrophic interactions in a new model system, study the co-evolution of protist:prokaryote interactions, discover the symbiont diversity in one particular lineage of eukaryotes known to harbour syntrophic symbioses (‘breviates’).