Team:UNebraska-Lincoln/background
Background
The Haber-Bosch process is used to produce reactive nitrogen, specifically for fertilizers. This process produces approximately 100Tg of reactive nitrogen per year (Chen, Ling-Hsiang). It is clear we can effectively produce reactive nitrogen, however, we need to clean up after ourselves by completing the nitrogen cycle. There is a lot more reactive nitrogen being introduced to the environment, but the rate of denitrification has essentially stayed the same. Our team will focus on denitrification, in an effort to restore safer nitrogen levels in waterways and bodies of water and ultimately to help make the completion of the nitrogen cycle more efficient.
Nitrogen is a highly abundant element in the Earth’s atmosphere. Nitrogen is also essential for life. However, atmospheric nitrogen (N2) is not useful in living processes. Humans have developed processes to convert unreactive atmospheric nitrogen into a usable form of nitrogen such as Ammonia or Nitrate for plants and animals (reactive nitrogen). To maximize crop yield, many farmers add nitrogen based fertilizer to their crops. Oftentimes excess nitrogen in the soil is washed away by rain into other natural water systems. This nitrogen runoff can and does have devastating effects on the biodiversity in waterways. Excess nitrogen in waterways can cause eutrophication, where algae take advantage of the excess nitrogen, causing much larger algal blooms. The algal blooms eventually lead to a dramatic reduction of dissolved oxygen in the water, which causes a dead zone where little to no aquatic animals and plants are able to survive. An example of a dead zone largely caused by excess reactive nitrogen is the dead zone in the Gulf of Mexico which measures up to 6,000-7,000 square miles (M. Bruckner).
Our focus for this year is on the first step in the denitrification pathway, turning nitrate into nitrite. We hope that by over-expressing a naturally occurring nitrate reductase, we can create an organism that is capable of cleaning up the excess nitrate that is found in many waterways.
1. Bruckner, Monica. "The Gulf of Mexico Dead Zone." Microbial Life Education Resources. Montana State University, n.d. Web. 19 Oct. 2016..
How did we do this?
