A Mathematical Model of Gene Regulatory Network of Pseudomonas aeruginosa under Denitrification

Lake Erie is one of the Great Lakes in North America and has a favorable environment for agriculture in which nitrate (NO₃) is widely used as fertilizers. On the other hand, it has witnessed recurrent summertime oxygen depletion and related microbial production of greenhouse gases such as nitrous oxide (N₂O). In fact, N₂O is an intermediate in denitrification, which is a microbial process of conversion of nitrate (NO₃) to nitrogen gas (N₂). This presentation will introduce the gene regulatory network and its (discrete) mathematical model of Pseudomonas aeruginosa, one of the microbes performing denitrification in Lake Erie. Polynomial Dynamical Systems (PDS) is used to model the network, and the model is analyzed by changing the concentration level of some environmental parameters such as oxygen (O₂), nitrate (NO₃) and phosphorus (P) to see how these parameters affect the long-run behavior of the network. Analysis is done in Analysis of Dynamic Algebraic Models (ADAM available at http://dvd.vbi.vt.edu/adam.html). Our goal is to generate some hypotheses leading us to the reason of accumulation of greenhouse gases in Lake Erie, which is still unknown.