We develop high-throughput, time-resolved mass spectrometry methods to measure enzyme activity in systems too complex or poorly characterized to study one enzyme at a time. These include microbial enzyme mixtures, structurally complex substrates that can be transformed through multiple reaction pathways, and enzymes under active regulation.

A major focus is the marine carbon cycle, where enzymes control polysaccharide degradation, microbial cross-feeding, and whether dissolved organic molecules are rapidly consumed or persist for millennia. We apply the same methodological framework to fundamental questions in microbial physiology, using kinetic measurements of enzyme activity as the unifying thread.