Grace Pold

I am a microbiologist and currently associate senior lecturer in Soil Nutrient Cycling. My research uses a combination of cultivation, bioinformatics, and modeling to understand connections between the carbon and nitrogen cycles.

My currently funded research projects are:

Does it flex before it breaks? Determining the roles of metabolic flexibility & species sorting in community response to a changing environment using denitrification as a model process (Swedish Research Council VR; 2024-27)

In this project we are evaluating whether bacteria which can "breathe" nitrite all the way to dinitrogen are fundamentally different to those which can either only complete the first or last steps in this process. In particular, we are testing the hypothesis that organisms with more ways to get rid of electrons also have more ways to get them in the first place. 

Can understanding how microbes compete for soil organic matter help us design better strategies to mitigate the greenhouse gas nitrous oxide? (Carl Trygger)

In this project, we are assessing the degree to which organisms which produce and consume each-other's electron acceptors also produce and consume one-another's electron donors. Many organisms which are capable of both producing and consuming nitrous oxide tend to produce nitrous oxide and only later consume it, so the idea is that if there are nitrous oxide consuming organisms which closely associate with or consume metabolic byproducts of nitrous oxide producing organisms while they produce nitrous oxide, these emissions may be reduced.

The broader objective of both the aforementioned projects is to identify the conditions under which organisms may be "encouraged" to complete the last step of denitrification and convert the greenhouse gas nitrous oxide to dinitrogen, whether they be specialists in this step or also responsible for producing nitrous oxide.

The many faces of nitrate ammonifying bacteria – Unraveling their role in nitrogen retention and loss, and nitrous oxide emissions in terrestrial ecosystems (Swedish Research Council VR; 2024-27 PI Sara Hallin,  co-applicant Aurélien Saghaï)

In this project, we are addressing why bacteria might encode the apparently competing pathways of denitrification (in which nitrite is converted to the greenhouse gas nitrous oxide or dinitrogen) and DNRA (in which nitrite is converted to ammonium and stays in the soil in a plant-available form).

At the undergraduate level, am course leader for the lab section of Molecular and Microbial Ecology (BI1438) and the Soil Biology section of Markvetenskap för miljö och vatten (MV0192). At the PhD level I am co-organizer of the "Molecular methods in microbial ecology" course with Karina Clemmensen and the "Soil Systems: integrating chemical and biophysical interfaces" course led by Elsa Coucheney.

I am also always looking for eager masters and bachelor students to work with me on topics listed in my research profile.

Bachelor of Science in biology with minor in environmental sciences - McGill University

Master of Science in microbiology - University of Massachusetts Amherst

PhD in Organismic and Evolutionary Biology - University of Massachusetts Amherst