Bactissiles: The future of microbial combat

Destabilized ecosystems and disturbed gut floras are both consequences of treatments that lack selectivity. More efficient and precise methods are needed. This year we, the Uppsala iGEM team, tries to widen the view and find new possibilities with engineered bacteria. By developing a system that homes towards a target and secretes an affectant, we can ensure a specific outcome. Such a system could have applications in a number of different fields, though we have chosen to put this into practice in a pinpointing pathogen-killing approach. In our prototype system, introduced in E. coli , we hijack the quorum sensing system of the gut pathogen Yersinia enterocolitica . Our bacteria will be able to sense the presence of the pathogen, accumulate in its vicinity and emit a target-specific bacteriocin, leaving the remaining gut flora intact. The era of mass destruction is over. Welcome the missile bacteria, the Bactissile! .

Assembly Plan

Main Result

Sensing Result

Graph 1. The production of the green fluorescence protein GFP in cells containing the following constructs: 1. pSB3C17-B0032-yenbox_WT-GFP 2. pSB3C17-B0032-yenbox_WT-GFP + pSB1K3-J23101-B0034-YenR 3. pSB3C17-B0032-yenbox_WT-GFP + pSB1K3-J23110-B0034-YenR 4. pSB3C17-B0032-yenbox_WT-GFP + pSB1K3-J23102-B0034-YenR

By constructing the measuremnt construct BBa_K1381008 (yenbox_WT-B0032-GFP) and performing double transformation together with one of the constructs producting the activator YenR BBa_K1381005 (J23110-B0034-YenR), BBa_K1381006 (J23102-B0034-YenR) and BBa_K1381007 (J23101-B0034-YenR). We managed to show that the activator YenR works perfectly fine in E. coli and that it recognise the recognition region, the yenbox and induces the strength of the promoter fused with it. By measuring the production of the green fluorescence protein GFP using a flow cytometer, we could see that we got a five-fold induction when YenR with the strongest promoter out of the three used were present.