Design of reagentless biosensors for the systemic herbicide glyphosate

The herbicide glyphosate, better known by the name of its most common commercial product, ‘Roundup’, is a broad spectrum herbicide that is used extensively in agriculture. Glyphosate can enter surface and subsurface waters and can be partially degraded to aminomethylphosphonic acid (AMPA), which can be used by some microbes as a sole source of phosphate. AMPA levels also provide an indicated of glyphosate contamination in the environment. Both compounds are widespread in the environment, but are poorly monitored and as organophosphates could have impact on environmental safety & human health.
In the project the student will use a variety of microbiological, biochemical and structural approaches to develop a protein-based biosensor that can be used by FERA scientists to detect glyphosate and/or AMP in the field.
The novel route we have identified that will be the main focus of this project is to use bacterial transporter component called substrate binding proteins (SBPs), which are known to be highly specific for particular ligands, and which undergo a large conformational change upon ligand binding that can be exploited in a functional biosensor. The project will involve the engineering of known SBPs and also the characterisation of novel SBPs from either known or newly isolated bacteria that are able to glyphosate as the sole source of phosphate. An SBP optimised for selective AMPA or glyphosate binding will then be developed in Fera for use in a biosensor device. The project builds on complementary skills in microbiology, biochemistry of protein-ligand interactions and protein engineering at the University of York and the analytical and biosensor expertise at Fera.