Team:Paris Bettencourt/Applied Design

Applied Design

Piglets reared across France are given antibiotics to protect them against the infectious diseases. As antibiotic resistance spreads through many routes. Animal consumption is one of them, and pork is widely consumed among the French population, we thought this field could be one of domains where antibiotic consumption could be reduced.

Our team proposed to replace antibiotics by our StarCore, thus, we devised a strategy to construct new modular antimicrobial peptides. StarCore is a fusion of antimicrobial peptides to self-assembling multimeric proteins, thus creating a star-shaped complex.

Using the synthetic biology tool of Golden-gate assembly, we designed 210 combinatorial fusions of 15 peptides and 14 cores. Golden-gate assembly, based on Type IIG restriction enzymes allow scar-free cloning, thus, we had successfully constructed more than 60% of our proposed StarCores.

Cell-free expression permitted us to obtain 11 StarCores, which showed a dose-dependent antibacterial activity, in range comparable to commonly-used antibiotics. Out of which, two StarCores were submitted as BioBricks BBa_K2738006 and BBa_K2738104, with the former killing E.coli and B. subtilis and the latter only inhibits Bacillus growth. On additional characterisation of the safety profile, we indirectly showed that they are not toxic by liposome assays.

Although, we proposed to develop an efficient system for easier and faster production of modular AMPs, our system failed to give us high concentrations of protein. Our cloning system is handy and effective, but we need to standardise the cell-free system of production to increase protein production.

In the end, the social impact and utility of StarCores was complied, we found that the public is quite was unaware of the grave situation and our game Makism- the Piglet was an exciting eye-opener for all, be it young or old.

Finally, the iGEM journey has showed us that the need of the hour is devise a system to produce eco-friendly, broad-spectrum StarCores, to replace the antibiotics commonly, to help the curb the spread of antibiotic resistance.