Team:Stanford-Brown-RISD/Safety
The Organisms We Worked With
- Escherichia coli (Main chassis organism) Strains used: NEB5alpha High efficiency DH5alpha derivative strain K12. T7 express BL21 derivative, strain B.
- Ganoderma lucidum
- Arthrospira platensis
- Anabaena variabilis
- Mucor circinelloides
- Bacillus subtilis
These are all common widespread species without serious health effects. They are all generally regarded as safe (GRAS), Biosafety Level 1, and are found commonly in the natural environment.
What risks could arise from our experiments?
A possible risk is the release of fungal spores into the lab. However, none of the strains of fungi we worked with are known to produce spores hazardous to human health, and we have tailored the growth conditions so that the growing fungi should remain in the non spore-forming mycelial stage. Even so, we wrapped or sealed all growing mycelium into separate containers, and sequestered all of said containers into one environmental growth chamber to limit the possibility of spore release. Any fungal samples we suspected would send out contaminating spores if opened were worked on under a sterilized laminar flow hood. After adequate mycelial growth has occurred, we also baked the mycelium to dry and inactivate it and prevent further growth while keeping it out of wet or damp conditions that could restart growth.
What risk might our project pose outside of the lab?
More than likely, little to no risk. The strains we are working with are regarded as safe and are will not have any toxic or virulent modifications. No modifications will be made beyond the overexpression of adhesive proteins, which should not affect the environment, our colleagues, the community at large, or us even if they escape the lab. Also overexpressed protein production would stop or drop to near negligible levels after the cells run out of the induction molecules arabinose or IPTG, the latter of which is not very common in nature. For housing applications, it is important that our mycelia has adequate structural integrity - we have begun to address this concern via materials testing. For filtration, one risk is that the mycelia will somehow contaminate the actual water being run through it - and one way we are addressing this concern is by killing the mycelia before using it to filter water. For off-earth applications, it is also important for our bacteria/mycelia to not contaminate the planet. Based on discussions we had with NASA's planetary protection officer, we have incorporated additional precautions against interplanetary contamination (including killing bacteria/mycelia via extreme heat, and only growing mycelia within plastic shells to limit exposure to the planetary environment). Thanks to our multiple post-doctoral advisers with many years of synthetic biology lab and safety experience, our primary investigator, and government-mandated inspectors from NASA for ensuring careful training and vigilant maintenance of safety standards.