"
Team:Fudan-Shanghai/Project
From 2011.igem.org
|
|
Detail:The project “E.tree” is consisted of two genetically modified E.coli: E. trunk and E.leaf.E.trunk detects nitrates in the medium; if KNO3 is present, the first circuit is activated, RhlI produces the AHL (C4-homoserine lactone) and TetR is synthesized to block the second pathway. If the medium lacks KNO3, the first pathway is off while the second pathway is activated and LasI produces an AHL autoinducer (3OC12-homoserine lactone). E.leaf changes color corresponding to the signal molecules released by E.trunk. RhlR synthesized in E.leaf binds to the RhlI-directed signal, and the complex then interact with the pRhl promoter and yellow pigment is produced. This circuit also encodes RhlI, which multiple the circuit, so that all E.leaf would turn yellow. Similarly, if E.trunk releases 3OC12-homoserine lactone, which is encodes by LasI, all “leaves” would turn green. |
 |
Part I: E.Tree
|
|
Detail:In the project of neon lights, we intended to have E.coli engineered for emitting one color of fluorescence during exponential phase and another color during stationary phase, so that it is convenient to identify the phase and may also be utilized for other purposes. To achieve this goal, we chose BBa_J45992, a stationary phase promoter, and BBa_J45996, only active during exponential phase. Then we tried to produce different luciferases under the control of the promoters. Parts of various luciferases have been obtained by the team of Cambridge in 2010, for example, BBa_K325210, BBa_K325229, etc. System of degradation, such as ClpXP, can be used to optimize the project by degrading the previous luciferase when the latter is being produced, to make the latter color purer and the process of color changing faster. In addition, the fluctuation of the lusiferase activity due to the growth should be taken into consideration. |
 |
|
|
Detail:The hungry customer gives signal "luxI",which means order the dinner. The "chef" containing luxr which can sense the "order" signal starts the generation of "dinner"-----luxpR. The dinner service is companied with yellow fluorescent,given by the expression of YFP by the "chef". When the "customer" is satisfied with the dinner, it gives the signal of RFP and expresses aiiA to inhibite the generation of luxpR and stop serving the "dinner". |
|
 |
|
