IGEM:Paris Bettencourt 2012/Notebooks/Delay group

Notebook	Design	Roadmap	Meetings and to-dos	Protocols	Bibliography	Previous Biosafety iGEM projects

Delay group

---

The aim of that subproject is to find a way to launch the destruction of either the construction or the organism after a certain laps of time.

Here we report the idea we have, and how we could make them real.

Alginate beads

Here, we would place alginate beads, with controlled alginate matrix size into the capsule. The alginate beads contains theophylline, that would act as an activator of a riboswitch that would repress gene expression [1]. This riboswitch would be fused into the 5'-UTR of the gene we want to repress (see figure 1). That gene would be one of the colicin gene, that can diffuse and kill other Enterobacteriaceae. The colicine gene is under Rpos promoter which is activated when bacteria is on stationary phase. So, bacteria will die on stationary phase and when theophylline is under a certain threshold, thanks to its diffusion through beads and capsule.

Figure 1 : Theophylline riboswitch, adapted from [1]

References

1. Topp, S. & Gallivan, J.P. Riboswitches in unexpected places -€” A synthetic riboswitch in a protein coding region. RNA journal 2498-2503 (2008) Paper