Team:Penn/Overview
The 2015 Penn iGEM team presents light as a viable alternative to conventional chemical quorum sensing suitable for applications of light-based cell communication. In response to accumulating autoinducers, quorum sensing enables microorganisms to modify gene expression as a function of cell density. However, these chemical signals restrict communication to within common environments and compatible conditions. In electronics, when electrical signals must be transferred between two isolated circuits, electrical engineers use an optocoupler. In a similar approach, we used genes involved in luminescence and genes sensitive to light to create a genetic optocoupler, enabling the transfer of genetic signals between isolated cells. This year, we showed that light can elicit a response in a light-sensitive receiver. The team further illuminated potential applications for this alternative form of cell communication.
We characterized a fascinating and underused organism: Magnetospirillum magneticum (AMB-1), a bacterium that aligns with magnetic fields. AMB-1 had previously been incorporated in very few publications. By developing, testing, and optimizing protocols for its growth and transformation, and then making them easily accessible in a convenient Strain Spec Sheet, we hope to establish AMB-1 as an easily engineered organism. We also tested and troubleshot the few genetic parts used in AMB-1 engineering, and then designed a new, BioBrick-compatible vector with an AMB-1 specific origin of replication, promoter, and multiple-cloning site. We are currently characterizing this vector, pMAGMA3.
In the future, AMB-1 has high potential for use in novel synthetic biology applications because of its capacity to align with magnetic fields. We are especially interested in using AMB-1 for bioremediation applications, such as cleaning pollutants from water. Many engineered microbes can absorb pollutants, but if AMB-1 were used instead of E.Coli, it could be subsequently removed from the water with a magnet – effectively removing both the pollutant and the engineered microbe. To help prove this concept is feasible, we ran experiments to test that AMB-1 can survive in water polluted with the heavy metal, cadmium.
 |
 |
 |
 |
| Magnetism of AMB-1 | Microbiology in AMB-1 | Synthetic Biology in AMB-1 | Cadmium Tolerance in E. Coli vs. AMB-1 |