Ate Hendrik-Jan Jaarsma

MSc, PhD Student

Ate Hendrik-Jan Jaarsma



PhD project:Survival, growth mechanisms, and biotechnological potential of microorganisms on the Greenland ice sheet

University: Aarhus University
Department: Department of Environmental Science

Section:Environmental Microbiology and Circular Resource flow – EMCIF

Research group: Cryo microbiology
Supervisor:  Alexandre Magno Barbosa Anesio           
Co-supervisors: Peter Stougaard, Mariane Schmidt Thøgersen
Project term:
 01.09.2020 – 30.08.2023
Master’s degree: MSc in Biomolecular Sciences, University of Groningen, The Netherlands


Microbial competition is widespread in nature. In the fight for space and nutrients, competitive phenotypes (causing a fitness decrease in a competing strain) can manifest itself in various ways. As the ice sheet biome is mainly microbially driven, it is worthwhile to investigate the interactions between organisms in the microbial community in this particular environment. Researching the competitive strategies of psychrophilic microbes may provide new insight into the nature and intricacies of microbial interactions in the ice sheet biome.


Insight into microbial competition may fill in missing fundamental knowledge on survival strategies of microbes in the cryosphere. In addition to the clear physiological adaptations, microbes might use more harsh techniques to ensure their survival. Knowledge of these mechanisms is useful in understanding how this ecosystem is maintained or may change in the future.

Apart from the fundamental knowledge, there lies biotechnological potential and value especially in the biodiscovery of antimicrobial compounds, as there is an urgent need for novel antibiotics. Under-investigated extremophiles may provide an untapped reservoir of chemical diversity that is not yet exploited. Discovery of antimicrobials and other competition systems may thus be a stepping stone to the use for human benefit. This is also true for other cold-active enzymes that may be exploited for industry purposes.


Microbes on the Greenland ice sheet likely make up a network of countless interactions between them. As a molecular biologist, I want to keep the microbial ecology as a backdrop, but zoom in on specific interactions between microorganisms. In particular, antagonistic behaviour is of interest, as this “chemical warfare” is not only linked to growth inhibition, but can have functions involving kin-recognition and signalling as well. Conversely, growth promoting interactions are of interest as well. I plan to screen for said phenotypes through co-culture studies and inhibition assays in an effort to isolate and characterize novel bioactive compounds.

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