Team:Strasbourg/Safety

iGEM

Figure 1: What we don’t want!

Safety and Securities

Our work led us to the implementation of the three-hybrid system into two different E. coli strains: FW102 OL2-62 and SU202. As far as the classification of organisms is concerned, such laboratory strains are indexed on the White List thus allowing us to carry out our experiments under a biosafety level 1. It is noteworthy to mention that aptamers and other catalytic RNAs are as well classified on the White List. Characterization experiments were also performed with the DH10-beta strain.

The aim of our project being to apply our system to the detection of allergens in food, on-site detection by individuals would be possible by its implementation within a portable enclosed device. Besides the technical characteristics of our prototype, we have reflected the safety concerns of such a controlled release.

The first step has been to assess the risk. It means identifying harmful properties towards human health and the environment in the case of unintentional release and further estimate their probability of occurrence. The genetically engineered bacteria are derivatives from common laboratory E. coli strains known to be innocuous. The major concern towards health lies in the antibiotic resistance. Indeed, our strains and plasmids carry resistance against kanamycin, chloramphenicol, tetracycline, ampicillin, spectinomycin or streptomycin. Horizontal gene transfer from our engineered bacteria to native ones could confer them resistance against the aforementioned antibiotics which are nowadays still of use for medicine. Since probability should be considered, the frequency of gene transfer could be increased in the case of such a resistance. Not only are these antibiotics of use for human health but also for veterinary medicine. Streptomycin is even of interest in agriculture. As far as the environment is concerned, the balance between native and engineered micro-organisms would be at stake in the case of containment failure. Furthermore, the portability of such a device would put a wide variety of ecosystems at risk.

The second step is to mitigate these risks, prevent their occurrence as well as implement solutions to manage them in case of uncontrolled release. Many strategies are currently developed to handle risks related to synthetic biology ; introduction of a kill switch sensible to abiotic factors, a metabolite dependency or a chemical containment enclosed in our device are as many ways to prevent any survivability outside of the apparatus. The insertion of a barcode within the DNA would allow to track any genetically engineered organism in the environment back to its laboratory of origin. Disposal of wastes should also be of concern.

We have identified some bottlenecks for the risk management of our device upon commercialisation. Further genetic engineering would thus be necessary to meet effective biosafety. Regulations and directives from the European Union are still vague concerning such a GMO-based technology. Nevertheless, more and more studies aim at estimating risks related to the fast-growing field of synthetic biology.

Figure 2: Safety installations at the IGEM Strasbourg laboratory.

References

  1. iGEM 2019 Safety Resources
  2. Wang, F., Zhang, W. 2019. Journal of Biosafety and Biosecurity 22-30.