Soil, Water, and Environmental Science

Created by living things, metabolites or organic compounds are found throughout the world. They have various functions and influences on the environment, yet their varied response to environmental change makes determining their role in the ecosystem challenging and hard to implement in current ecosystem models. Given that many ecosystems are undergoing rapid environmental changes, obtaining a process-level understanding of the mechanisms that affect metabolite production and transformation in soil systems and their function and interactions is important for predicting greenhouse gas emissions. Additionally, the majority of metabolites in the environment are either unknown or of unknown structure, thus illuminating the dark matter in metabolomics remains another need in my field. Investigating these research questions has not been easy, in part because it requires an integrative multidisciplinary approach that includes chemistry and biology. My training as an analytical chemist provided me the unusual opportunity to learn and apply multi-omics techniques including metabolomics and ultra-sensitive chemical characterization to further advance my capability to identify the molecules and mechanisms that are the correlative basis of ecosystem C cycling science and illuminate this dark matter. Additionally, my approaches are integrative and readily translatable across biomes, diverse ecological settings, and the agricultural/wildland interface.

Joan Curry, PhD, stands in the field of research related to interfacial chemistry, which is a focus within physical chemistry. Within interfacial chemistry, she focuses on chemistry of molecules at the interfaces where solids and liquids come together. The term solid here includes mineral and bacterial surfaces found in soils and sediments, metal and oxide machine surfaces and cell surfaces found in the human body. Molecules can be water and ions that bathe soil surfaces, organics that lubricate machine parts and large biomacromolecules, such as proteins and lipopolysaccharides, attached to cells that mediate cell adhesion. Her specific interests are: 1) determining the effect of confinement on liquids in general and lubricants in particular and 2) characterizing the adhesive properties of cell surface biomacromolecules. The primary goal of this work is to understand how biomacromolecules that cover cell surfaces influence the interaction and adhesion of cells with other cells and with solid surfaces. Cells can be either bacteria or human cells. It is important to understand bacterial adhesion because it is the first step in biofilm formation, which has numerous undesirable consequences ranging from heat exchanger fouling to medical implant infections. Currently, very little is known about how bacterial surface biomacromolecules mediate adhesion and therefore it is still not possible to control or manipulate the process. Human cell adhesion is also mediated by biomacromolecules, in particular proteins that bind to one another through specific lock and key mechanisms. The structure of many cell adhesion proteins is well known but their function is still poorly understood. In collaboration with Ronald Heimark (Surgery), Dr. Curry is working to understand how heavy metals such as cadmium affect the binding of cell adhesion proteins called cadherins. This work will help scientists understand better how heavy metals may lead to birth defects and in adults could accelerate cardiovascular disease. This work is experimental and involves direct force measurements between biomembrane covered mica surfaces with the Surface Forces Apparatus (SFA). With the SFA it is possible to measure the magnitude and distance dependence of molecular forces acting between two flat surfaces with angstrom and nanonewton resolution.