Life on Earth exploits its chemical environment for energy and biomass. Microorganisms, in particular, are exquisitely sensitive to chemical changes in their surroundings and the composition of microbial communities co-evolves with the composition of dissolved growth substrates and nutrients. In aquatic systems, a significant pool of growth substrates resides within dissolved organic matter (DOM), which plays a fundamental role in the global carbon cycle as one of the largest reservoirs of reduced carbon on the Earth’s surface. The Kujawinski laboratory has focused on this interdisciplinary theme through multiple research efforts. These efforts involve the characterization of DOM in different aquatic environments and focused studies of the effect of abiotic and biotic processes on DOM composition in the oceans. A portion of our research can be described as marine metabolomics. Throughout these research activities, the lab has combined fundamental work in analytical chemistry, chemical oceanography, microbiology and microbial ecology to elucidate the controls on DOM composition in aquatic systems.