Module 6: Containment

Description | Design | Construction | Characterisation | Modelling | Results | Conclusions

Conclusion

We have successfully transformed our cells to produce a periplasmic nuclease, a necessary feature to prevent transformation of wild-type cells in the marine environment. Furthermore, we have proven that this BioBrick does not adversely affect the viability of our cells, allowing it to be utilised as part of a containment system for engineered cells. This also demonstrates that DsbA signal works otherwise the nuclease would have caused cell death as cytosolic nucleases are lethal and more commonly used as kill-swithces

Our DNAse assay is helpful not only for identifying the activity of our nuclease but also this is a nice system to quickly show if DsbA-mediated periplasm trafficking is possible.

We successfully demonstarte that material from cells containing our Biosafety BioBrick is not able to transform commercial competent cells. This suggests periplasmic nuclease expression provides a promising strategy for preventing transfer of genetically modified DNA. This is particularly valuable for the application of synthetic biology in environmental contexts.

In addition to this we are able to predict nuclease activity which correlates to the colony mass. This shows that containment model is realistic.

Future work would attempt to construct a three-fold containment system, in order to create a more robust system capable of prevent other mechanisms of horizontal gene transfer, such as transduction and bacterial conjugation.