Carbon monoxide (CO) poisoning is one of the most harmful types of air poisoning around the world. CO gas is mostly released from the internal combustion of engines as well as the use of fuels such as wood and coal. Since CO is highly produced in urban areas, it presents a big danger for any living organism. The aim of our project is to convert CO into CO2 biologically, which then can be converted into oxygen with photosynthesis by photoautotrophic organisms. In order to achieve this, we plan to construct a biofilm containing the enzyme Carbon Monoxide Dehydrogenase (CODH). With the production of this biofilm, it may be possible to obtain a biological filter that can fix the ratio of CO and CO2 present in the environment. We also try to integrate a kill switch, previously developed by Berkeley, to our system for safer use of our biofilm as well as a cell limiter for better characterization of the biofilm activity