In recent years the environmental impact of nitrogen oxide (NOx) gases has become a pressing concern due to increases in anthropogenic sources, particularly diesel car emissions. NOx gases are both a health risk, producing toxic ozone in the troposphere, and an ozone-depleting substance (ODS) in the stratosphere, contributing to climate change. NOx gases were not included in the Montreal Protocol (1989), which aimed to tackle the environmental impacts of ODSs such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), resulting in uncontrolled NOx pollution. Therefore the control of NOx has been less successful compared to other ODSs. NOx is now the third most detrimental greenhouse gas, behind only CO2 and methane. In our project, we will genetically engineer E. coli to metabolise NOx, using the cytochrome c nitrite reductase (NrfA), which reduces nitrite (NO2-) to ammonia. This ammonia can then either be used to make fertiliser or be enzymatically converted to urea for the possible production of electricity, when fed into a urine-powered microbial fuel cell (MFC). We will also incorporate a fluorescent reporter gene to provide a measure of ammonia production and create bioluminescence for street lighting; this may be more aesthetically pleasing to the general public. We plan to use our model of local NOx concentrations in Bristol to strategically place our recombinant bacteria in problem areas within pod structures, and aim to assemble them into larger synthetic trees, which are either self sustaining or require low maintenance.