The biosensor is the heart of our project and because it took us a lot of time to create. Like it is already explain in the Biobrick Design section, this biobrick is composed of the Pr promoter (BBa_K2023004) which is a constitutive promoter driving the transcription of the XylR gene (BBa_K2023005) coding for the XylR protein. The XylR protein is able to bind aromatic hydrocarbons that carry a methyl group like toluene and xylene. When XylR has bind toluene for instance, it is able to regulate the Pu promoter has a transcriptional regulator. Then, Pu is activated and it allows the transcription of the bioluminescent reporter gene GLuc (Pu+GLuc: BBa_K2023003), coding for the Gaussia luciferase. When this enzyme reacts with its substrate luciferine, a substance called Coelenterazine, it emits luminescence.
Those 3 parts are probably the most important because they are the fondations of the biosensor right above. We designed and ordered the sequences to Integrated DNA Technologies. We first assembled BB1 and BB2 in pSB1C3 to create BB12 and then we had BB3 in order to produce BB123 the biosensor.
