The Wackett laboratory investigates bacterial biodegradative metabolism and enzymes of the herbicide atrazine and related compounds, see for example the UM-BBD atrazine pathway elucidated by our group. Bacteria initiate metabolism of atrazine via the enzyme atrazine chlorohydrolase for which we first reported the structure (Seffernick, et al, 2010). The lab has defined the novel cyanuric acid hydrolase protein family (Seffernick, et al, 2012) and has recently described the X-ray structure for the enzyme from Azorhizobium caulinodans, shown at right.
The studies on biodegradation provide opportunities for bioremediation of chemical contaminants in water. The chemicals treated are atrazine, cyanuric acid, acrylamide, polycyclic aromatic hydrocarbons, benzene and substituted aromatic compounds. Biodegrading microbes are being deployed in silica microspheres. The silica encapsulation istabilizes the in vivo enzyme activities and makes a formulation that can be stored and used as needed. The biosilica can be fabricated as plugs, beads or within nano-filaments. This technology has allowed us to explore the treatment of heavily contaminated waters derived from hydraulic fracturing operations that contain additives and shale hydrocarbons.
Bacterial hydrocarbon biosynthesis
Industry is interested in renewable hydrocarbons as potential fuels, waxes and lubricants. Our research investigates the fundamental mechanistic and structural issues underlying biological hydrocarbon synthesis. Studies are focused on the biosynthesis of olefins and diesel-length alkanes.This research has been funded by the Institute on the Environment and ARPA-E. The enzyme aldehyde deformylating oxygenase uses a diiron center that resembles the clutser in soluble methane monooxygenase and our research has shown that the enzyme can catalyze adventitious oxygenation reactions (Aukema, et al 2013).
We had previously worked with Bioo Scientific to help develop the MaxSignal Melamine kit for detection melamine in milk and other food products. This research has been extended to detect other food toxicants as part of a project funded by the National Center for Food Protection and Defense, operating under the Department of Homeland Security. This research has been extended to other chemicals to make routine detection methods for field operations.
The laboratory continues to study novel microbial enzymes that nature has evolved to handle millions of natural product and anthropogenic chemicals. This has led to the discovery of numerous novel enzymes and metabolic pathways.
- Azetidine-2-carboxylate hydrolase X-ray structure
- Atrazine chlorohydrolase X- ray structure
- Thioamide biodegradation pathways
- Organoboronic acid metabolism