Using cultivation dependent and independent methods to study the ecology and physiology of Asgard archaea in Aarhus Bay

Summary

In this PhD research we used cultivation methods and genomic methods to get insight into recently discoverd microorganism called the Asgard archaea. The Asgard archaea are a prokaryotic group of microorganisms that have a key role in helping to understand the evolution from prokaryotic to eukaryotic lifeforms, as they are the closest prokaryotic relatives to eukaryotes. Cultivation of Asgard archaea is challenging, as they grow very slowly and are only found in the environment in low relative abundances. Aarhus Bay sediments contain some Asgard archaea and after incubation we managed to enrich them from 1% to almost 50% relative abundances. We also did metagenomic and metatranscriptomic studies on samples from Aarhus Bay, to get insight into the metabolism and activity in the sediments.