Harnessing E. coli to Identify Polystyrene Microplastics
Microplastics (MPs) are broadly defined as plastic materials that are less than 5 mm in size. Exposure to MPs can be traced back to synthetic products used every day, yet the potential health consequences of MP exposure are unknown. The detection of the ultra-small MPs in environmental or biological samples pushes the limitations of our current technologies, and they cannot determine MP chemical composition at high throughputs. A recent study demonstrated the ability to quantify algae that bind micro-polystyrene (micro-PS) on their cell surface. Several peptides have been identified to potentially have specific protein-plastic interactions; however, they have yet to be used in an application for MP detection. In this thesis, the cell surface of bacteria was genetically engineered to express peptides previously shown to bind bulk PS materials in an effort to develop a novel identification method for the chemical composition of micro-PS. Genes of PS-binding peptides (PBPs) were inserted into plasmid DNA that could express the PBPs on the surface of Escherichia coli. A combination of Western blots and flow cytometry were used to validate the expression of PBPs on the cell surface, and the ability of these cells to bind micro-PS was assessed using flow cytometry.
microplastics, synthetic biology, Chemistry and Biochemistry, Honors College
Coral, N. (2022). Harnessing E. coli to identify polystyrene microplastics. Honors College, Texas State University.