Why we did it
The IrrE protein from Deinococcus Radiodurans helps cells survive in harsh environments. iGEM 2012 demonstrated that it enables survival at high salinity levels. We decided to further characterise this protein in terms of a higher salt concentration, oxidative stress and viscosity. This characterisation applies to our light bulb and to Barchitecture.
We decided to engineer E. Coli to bioluminescence in response to sunlight levels to produce an efficient eco-friendly source of street illumination. Since this product is meant to co-exist with the general population, it will require to be cleaned with highly toxic agents. Thus we require our cells to be slightly more resistant to toxic compounds (ie. peroxide as a disinfectant) to extend the lifespan of our bulb as much as possible. This is an essential part for our entrepreneurship, to make the bulb a sustainable product.
After working with BluePHA, a company focused on using synthetic biology for the fine design of nano-level microbial manufacturing, we decided to turn to PHA-based structure generation. At BluePHA, they have developed bacterial PHA production and secretion using a strain found at high salt concentration levels in Tibet. This hardy strain is able to produce a higher yield of PHA and thus is a more economical and effective PHA producing microbe. Since we could not get details on the genetic constitution of this strain, we decided to explore the IrrE protein from Deinococcus Radiodurans, which had been previously characterised by UCL 2012.
We measured optical densities over a period of 30 hours, with the cells containing the IrrE plasmid surviving, compared to controls. Our results give future iGEM teams the possibility of experimenting with cells in extreme conditions, relevant to their applications.