Team:Tsinghua-A/InterLab

Discription
Overview
    In our system, we have three characters. Warriors attack the enemies, farmers provide nutrients for everybody, while beggars sit there doing nothing.
    To contruct our farmers, we contructed a new part invertase(BBa_K2250000/BBa_K2250001/BBa_K2250003). Our E.coli MG1655 can not utilize sucrose as its nutrients. Invertase catalyzes sucrose into glucose and fructose, thus providing nutrients for all bacteria. See the intervase test for more details.
    To realize the role of the warrior, we utilized a kind of molecule called AHL([N-]acyl-homoserine lactones). There are several kinds of AHLs, which bind to different receptors with different affinity. AHL together with the receptor can bind to specific promoters and activate the corresponding gene. We want to design a gene circuit with orthogonality.In other words, we want the warrior to kill bacteria from the other group but not from its own group. To accomplish this, we did the orthogonality test to select the comparatively best pairs.
    After the construction of our warriors, we tested how the warriors really work. We have two standards to see if the warriors are fitted or not. First, the warrior must have good orthogonality. That is to say, the warrior must kill its enemies but not itself. Second, the killing ability must be neither too strong nor too weak. We carried out the killing test to test our warriors.
    From the killing test, we find that although warrior 2 is nearly perfect, but warrior 1 kills itself and is too weak. We modified the gene circuit in order to enhance the performance of warrior 1. We did this through changing promoters and adding the part TetR. We built a model to help us modify the gene circuit, see improved gene circuit. Apart from this, we a more thorough discussion on killing ability in model part ---regulation of killing ability.