Metals play a critical role in environmental and biological processes as essential micronutrients, harmful toxins/contaminants, and as useful tracers of physical and chemical processes. Organic molecules often control the fate of metals in the environment by affecting their solubility, reactivity, and bioavailability. While these organic ligands are fundamental to our understanding of global metal cycling and biological productivity, their chemical composition has largely remained a mystery. One of our main goals is to develop and employ new analytical approaches for characterizing these molecules using chromatography and mass spectrometry, thereby shedding light on their microbial sources, reactivities, and bioavailabilities.

The dissolution of minerals is a fundamental process that supplies essential micronutrient metals to plants and microbes. These organisms, in turn, have evolved diverse strategies to actively extract these metals, effectively controlling the rates of mineral weathering and the flux of elements into ecosystems. While the importance of these interactions is clear, the underlying molecular mechanisms, and the specific biomolecules and chemical reactions microbes use to solubilize minerals and mobilize metals in the environment, remain largely unknown. Our research uses novel analytical techniques to identify these key molecules and mechanisms. A central goal is to translate this fundamental knowledge into sustainable strategies for managing soil and aquatic resources.