Safe lab work
In the context of our project, we wanted to use three different chassis : E. coli DH5-α, Shewanella oneidensis MR1, and E. coli WM3064 (for the transformation of Shewanella oneidensis). We chose E. coli DH5-α for our sensing system for its useful properties in synthetic biology and as it is a non pathogenic class 1 organism. Shewanella oneidensis MR1 and E. coli WM3064 were also chosen because they are non-pathogenic class 1 organisms. On top of that, E. coli WM3064 is an auxotroph bacteria to DAP (diaminopimelic acid), a lysine precursor.
During our project, parts developed and used were safe and would not raise any concerns in terms of harm to humans, animals, or to the environment. However, an ampicillin resistance, part of the pSB1A3 vector, was used and managed carefully in order to avoid any dissemination of resistant bacteria into the environment.
Students part of the lab team (Casilda, Marie, Quentin and Julian) were all 5-year students from Sup’Biotech Paris engineering school. As part of our education, we all had received lab safety and security and practical trainings and done internships in research laboratories prior to starting our iGEM 2021.
In terms of local regulation on the use of GMOs (Genetically Modified Organisms) in the laboratory, the team followed French and European directives for “confined environment”, framing the use of GMOs in research and industry. This constituted in the request of a specific authorization from French authorities for the use of our GMOs, and the careful follow of safety and security rules in a Biosafety class 1 laboratory.
For the safety of our model and its implementation in our daily life, we thought of modifying our bacterial strains (E. coli and Shewanella oneidensis) to prevent any leakage. The goal is to make them auxotroph, so when they are not in contact with the medium containing all the essential metabolites to survive, they die. This could be done by targeting amino-acid pathways with a knock out on specific genes (ex : target ArgA, involved in arginine production in E. coli). Auxotrophy mutations will not be developed during the 2021 iGEM competition but are necessary for the final development of the project.
On top of the auxotrophy system, we also planned to develop a physical containment system in our device by designing a multiple layer structure around bacterial culture.