Safety
Considering the implications of synthetic biology tools to the world beyond the lab, It is important to maintain safe and ethical use of engineered organisms.
Lab Safety
Even a relatively innocuous chassis such as E. coli can be risky to use if improperly handled. To prevent our engineered microbes from being released into the environment, we followed our host lab’s guidelines for proper disposal of organic waste. To prevent exposure, we wore basic personal protective equipment in the lab at all times. This included appropriate clothing, covered shoes, lab coats, goggles, and disposable gloves.
When choosing bacteria to use in our microbial fuel cell for their special ability to degrade Terephthalic Acid(TPA), a by-product of PET plastic degradation, we were careful to select only BSL1 organisms. For example, we chose not to work with P. aureginosa, a BSL2 organism which can use TPA as a carbon source.
Some techniques involved using chemicals that are hazardous to inhale. When working with such chemicals, we were careful to only work under the fume hood. Flammables were stored in a separate cabinet and disposed of according to strict guidelines.
Safety in Collaboration
We transported materials between our lab and the Northeastern team’s lab in sealed containment to prevent release.
Safe Project Design
Since we were working on a prototype with possible real-life applications, we considered safety when making crucial decisions about important aspects of our design. iGEM suggests that teams consider the following questions when designing their projects:
Who will use your product? What opinions do these people have about your project?
Our product is intended to be used as a plastic-mapping and plastic-degrading device for ocean researchers and others concerned with the distribution of plastic in the ocean. The Seabin Project was very excited about Plastiback, and is interested in future collaborations. Parley for the Oceans also sent us a typical sample of ocean plastic. Read more about our human practices here
Where will your product be used? On a farm, in a factory, inside human bodies, in the ocean?
Because our prototype is meant to be used in the ocean, we envision a bioreactor design that ensures the engineered microbes act as a closed system that is not released into the ocean environment. (See schematic indescription.) The influx of plastic will make that difficult, but future directions for research will include solidifying design to prevent engineered microbes from escaping into the ocean environment. At our current stage of research, we have determined that PETase production exerts a significant metabolic load on our expression cells, making them unlikely to be able to survive in the ocean environment. Furthermore, E. coli have been shown to lose viability after exposure to seawater, suggesting they would not survive and proliferate if they escaped Plastiback 1. This being said, our future work includes testing bioengineered control mechanisms such as a kill switch or synthetic amino-acid dependency 2 to make the risk of escape and proliferation in the environment even smaller. Lastly, because the Delftia bacteria in the microbial fuel cell is not genetically modified, its escape does not pose a significant risk.
- How do we prevent small animals from getting trapped in the device?
- Will the device stay afloat and be easy to retrieve from the ocean?
If your product is successful, who will receive benefits and who will be harmed?
Direct benefits of a successful and efficient plastic-sensing system, such as Plastiback, will be felt by researchers looking to map the distribution of plastics in the ocean, who have no alternative to physical sampling. Plastiback’s contribution to ocean plastic research will affect how well the effects of plastic pollution are neutralized. The device has immense potential to be useful tool for protecting ocean ecology. Because the ocean surrounds us and touches each of our lives every day, this application will benefit the global community.
As part of the prototype stage of our design, we are considering the environmental impact of the product in the oceans. Future directions of our project are mechanical design solutions to the following important questions:
What happens when it's all used up? Will it be sterilized, discarded, or recycled?
At the end of a Plastiback’s life cycle, it will be retrieved, sterilized, and reused. Collected debris will go to appropriate waste management systems.
Is it safer, cheaper, or better than other technologies that do the same thing?
Based on our research, Plastiback is currently the only remote plastic detection device. Estimates of plastic in the ocean are currently derived from surveys by research crews hauling nets through the ocean and hand-counting pieces of plastic3. Plastiback, as an alternative to physical sampling, fills the gap in technology that can detect ocean plastic. Plastiback also has the added benefit of being able to collect plastic and degrade it, converting these fragments, especially microplastics which otherwise pollute the ocean and interfere with the lifecycles of marine organisms, into electricity.
Footnotes
1Rozen, Yael, and Shimshon Belkin. “Survival of Enteric Bacteria in Seawater.” FEMS Microbiology Reviews 25.5 (2001): 513–529. femsre.oxfordjournals.org. Web.
2Mandell, Daniel J. et al. “Biocontainment of Genetically Modified Organisms by Synthetic Protein Design.” Nature 518.7537 (2015): 55–60. www.nature.com. Web.
3Cressey, Daniel. “Bottles, Bags, Ropes and Toothbrushes: The Struggle to Track Ocean Plastics.” Nature 536.7616 (2016): 263–265. CrossRef. Web.
