20.109(S09)/PinkWF

20.109 Research Proposal for Derek Ju and Alvin Chen

Project Overview

Our goal is to rewire a bacterium to "miniprep" itself, when given some sort of an external stimuli (such as sensing of dense cell growth). This project will serve the following purposes:

• Make the research process easier, cheaper, and more efficient for scientists working with bacteria.
• Most laboratory strains have been genetically modified for scientific use; however our bacteria would be the first to be modified to do an experiment on itself.
• Self-lysing of cells when dense cell growth is encountered - less chance for environmental contamination if genetically engineered bacteria escape from the lab
• Serve as an example of a way synthetic biology can be used for cellular control
• Be an application of using irreversible switches within genetic circuits
• Be an example of sensors being built into bacteria

References

• http://www.nature.com/nature/journal/v403/n6767/abs/403339a0.html

Proteins bind to promoter regulatory sites to repress or activate expression. This results in two stable states: proteins (repressor) repress their own repressor, so they will remain stably expressed. But, switching is controllable switching: dominant repressor (state) can be de-activated with addition of inducer (IPTG, thermal shock, etc). This allows expression of the other repressor, and enables controllable state change of the system