I currently investigate the mechanism of biosynthesis of a polysaccharide adhesin secreted by Agrobacterium tumefaciens, a plant pathogen that causes crown gall disease in dicots.
Bacterial adhesion to host cells is often the first step in pathogenesis, and surface adhesion is necessary for biofilm formation in many bacterial species. The A. tumefaciens adhesin (unipolar polysaccharide or UPP) allows A. tumefaciens to adhere to both biotic and abiotic surfaces, is necessary for successful plant infection and biofilm formation, and plays a role in the ecology of A. tumefaciens.
Understanding how A. tumefaciens makes UPP will provide valuable insight into how other closely related plant pathogens and symbionts establish host associations. My research also offers potential agricultural (pathogenesis control) and biotechnological (bioadhesive production, biofilm control) applications.

My previous research involved the long-term evolution (LTE) of a bacterial co-culture comprising the fermentative bacterium E. coli and a purple non-sulfur bacterium (PNSB), Rhodopseudomonas palustris. Both bacteria were engineered to form a stable co-culture in minimal medium with glucose as the sole carbon source and nitrogen gas as the sole nitrogen source. In this system, E. coli ferments the glucose into organic acids that R. palustris can metabolize (R. palustris cannot metabolize glucose), while R. palustris, in turn, fixes nitrogen gas into ammonia which provides a useable nitrogen source for E. coli. Interestingly, both bacteria in co-culture produce more hydrogen gas (a potential biofuel) than each can produce individually. My LTE work explored the genetic co-evolution in the co-culture using molecular biology and several chromatography techniques. Furthermore, as part of my bacterial metabolism work, I helped discover that reductive tricarboxylic acid cycle enzymes and reductive amino acid synthesis pathways contribute to electron balance in another PNSB, Rhodospirillum rubrum.