An award is made to The University of Notre Dame to develop a remotely deployable yeast based biosensor that measures the amount of bioavailable phosphate in water. Eutrophication, pollution of surface water supplies through excess nutrients, can result in harmful algal blooms and the degradation of the quality of surface waters throughout the globe. Thus, the Broader Impacts of the project include helping to reduce the over abundance of nutrients in water supplies, protecting the environment, drinking water, and property values, and optimizing fertilizer use (reducing farming costs and conserving the limited resource phosphate). The education and outreach efforts will include development of a simplified batch-culture-based assay for use in schools and community settings, which will broaden environmental participation and awareness of the need to reduce phosphate waste. In addition, the analytical chemistry and ecology students involved in the project will each receive cross-disciplinary training in the other field.
Improving the technology for measuring phosphate is important because eutrophication (pollution through excess nutrients) is degrading the quality of surface waters throughout the globe, and monitoring of phosphate is largely still limited to laborious lab-based, wet chemistry approaches. The goal of the project is to address this problem by developing a biologically-based phosphate sensor that is continuous, relatively inexpensive, remotely deployable, able to test turbid water, and based on monitoring the growth of the yeast Saccharomyces cerevisiae. The principle behind the device is that all organisms (including yeast) need phosphate to grow; yeast are ideal organisms for this work for reasons including their robustness to environmental perturbation and resistance to water-borne viruses. Since yeast growth is linear with phosphate concentration in the relevant phosphate concentration range, changes in the amount of bioavailable phosphate in water will be measured by monitoring the growth and respiration of yeast in this continuous culture system under conditions where the test water is the only source of phosphate. Because this sensor will measure bioavailable phosphate, not simply dissolved reactive phosphate (DRP) or total phosphorous (TP) as measured by other standard approaches, it will represent an important new tool for any environmental or engineering studies involving freshwater and should provide insight into previously inaccessible aspects of nutrient dynamics in aquatic systems.