We wanted our project to address a problem of significance on both global and local levels. Because Nebraska’s economy relies heavily on agriculture, a project devoted to an aspect of this industry was the obvious choice. Our objective is to reduce the nitrate levels in the waterways around Nebraska. Runoff from land treated with nitrate-containing fertilizers causes the accumulation of these compounds in waterways, where they are carried to the Gulf of Mexico. According to the National Oceanic and Atmospheric Administration, the Gulf of Mexico is the second-largest dead zone in the world, measuring approximately 5,500-6,500 square miles.
A dead zone is a hypoxic area in a body of water where little marine life can survive. The excess nutrients in the water from fertilizers cause algal blooms at the surface. Because algae is not a good food source for other organisms in the ecosystem, it sinks and decomposes when it dies. The process of decomposition uses oxygen dissolved in the water, making the area uninhabitable for many species.
The team this year aims to genetically engineer E. coli to perform bioremediation on bodies of water containing excess nitrogen. Given Nebraska’s agricultural foundations more effective nitrate removal will help to reduce the high nitrate levels in our waterways and ultimately reduce the environmental footprint of our state. Our project aims to control the denitrification by converting excess nitrate ions back into atmospheric nitrogen, essentially completing the nitrogen cycle. Engineering E. coli to denitrify waters will involve introducing a nitrate-responsive promoter, corresponding bacterial ‘termination sequences’, and safety steps to ensure that the process can be controlled to the cells.