Nutrient availability is a key control on the growth and activity of microbes. Usually nutrient limitations are considered individually, but this ignores the reality of nature: often, many nutrients are simultaneously deplete.

Our understanding of the phenomenon of microbial growth when multiple nutrients are dilute is limited by lack of a unifed framework. Together with our collaborators at Rutgers University and ETH Zurich, we are working to fill that gap.

Further work will focus on the molecular basis and biogeochemical implications of nutrient colimitation.

The project uses mathematical modelling, concepts in theoretical biology, physiology and molecular analysis.

Proteins are the literal molecular machines that perform biochemical transformations within cells and connect the inner life of cells to the external environment. Protein activity, particularly of key enzymes such as the photosynthetic enzymes and nitrogenase, is an important biogeochemical parameter.

Protein activity can be modulated by changes in protein concentration (as we can measure through proteomics), but also through changes in protein 3D shape. Protein 3D shape can change dynamically over time due to protein-metabolite interactions, protein-protein interactions, and post translational modifications.

We are developing conceptually simple strategies to measure protein conformational changes in marine microbes. We work with collaborators at... read more

Trichodesmium is unique among nitrogen fixers. It fixes nitrogen and carbon simultaneously. This is risky behavior - why would Trichodesmium do this?

The project used cell culturing, physiology, label-free protoemics, quantitative proteomics, GC-MS, mathematical modeling and network analysis.

This work was published in 2022. There is a much larger body of literature/debate about how Trichodesmium manages nitrogen fixation and carbon fixation simultaneously during the photoperiod. You can review snippets of this debate here. Clearly there is more to understand about Trichodesmium’s molecular physiology, and we plan to continue investigating!