UCL iGEM 2020 is building a microbial fuel cell to tackle plastic pollution and freshwater scarcity
Plastic pollution has become one of the most serious environmental problems, affecting our oceans and marine life, as well as human health. Many plastics persist in the environment for hundreds of years, and the problem is only getting worse, as plastic waste flowing into the oceans is expected to nearly triple in volume in the next 20 years.
The UCL iGEM 2020 team decided to tackle not only this issue but also the problem of access to freshwater, which affects many countries around the world. To do that, they are using a synthetic biology technique to couple plastic degradation with water desalination in a device known as a Microbial Fuel Cell (MFC). By degrading the plastic from the oceans as well as desalinating its water in a single-step process, they aim to provide freshwater for irrigation purposes in countries affected by water scarcity, while reducing plastic pollution in the environment.
The students are representing the University College London at the International Genetically Engineered Machine (iGEM), a synthetic biology competition that brings together young people from more than 40 countries. The team recently joined the iGEM program on Just One Giant Lab (JOGL), a platform that is fostering open collaboration between iGEM teams working on the Sustainable Development Goals.
To learn more about the project, we interviewed the team members by email.
How did your project get started? How did you become interested in this topic?
Stefan Hristov:
Interest in global issues, I believe, is a common characteristic of any ‘iGEMer’. In fact, it appears that the overall purpose of this competition is to provide innovative and sustainable solutions to these global problems. At the very beginning of the contest, we were naturally drawn to the ongoing pandemic and started thinking of synthetic biology-aided improvements to Personal Protective Equipment (PPE), and filtration systems, to help tackle Covid-19. However, this was a global issue that we couldn’t escape from. The resulting lockdown left us with the only option of pursuing a dry-lab project.
We focused our efforts on improving and adapting previously proposed or published grand ideas to the iGEM format. Our team had two strong propositions that would satisfy a dry-lab project and would also be suitable for an iGEM format. On one hand, we had what will someday become a classic iGEM problem: Tackling plastic pollution, which has become a worldwide problem, by improving plastic biodegradation mediated by the newly discovered PETase enzyme. On the other hand, we had a strong case to tackle the global issue of freshwater scarcity by saltwater desalination driven by genetically engineered organisms. However, plastic pollution and desalination, we found, are heavily connected: an estimated 8 million tonnes of plastic end up in the world’s seas and oceans annually, contributing to a vast array of environmental damage. Furthermore, it appears that plastics are also a burden to desalination efforts: the efficiency of salt removal depends highly on the quality of water. The microplastics, which increasingly pollute the world’s seas and oceans, undermine the productivity of desalination technologies.
Our thinking was to propose a parallel resolution to these problems and combine our ideas by harnessing the energy of the metabolites produced via PETase PET degradation for desalination. Our project, which will be developed over two years, thus focused on the production of a Microbial Desalination Cell, which utilizes electricity-producing bacteria to drive passive electrodialysis desalination. We are hoping this proposal provides an elegant approach to tackling these two global issues in parallel, by using the bad for the good.
Why is your research important? What are the possible real-world applications?
Li Xu:
Current methods of plastic degradation are mainly landfill and incineration, which are not sustainable and highly polluting. On the other hand, adequacy of freshwater, even water for irrigation, is always a problem, with freshwater demand expected to increase with population growth and climate change.
Our research project aims to use bacteria to degrade plastics and generate electricity for water desalination. Compared with the current plastic degradation method of landfill, our project takes a shorter time. Compared with incineration, our project is more environmentally friendly and hardly leaves any carbon footprint. We have improved current plastic bio-degradation methods by combining two enzymes into a fusion protein to make plastic biodegradation more efficient. As a result, our research is important to both real-world situations and academic research.
Since our project is trying to solve both plastic pollution and water scarcity at the same time, we have proposed to launch our project in the places affected by both of these issues. We plan to establish various partnerships with plastic recycling plants and water treatment plants. Also, since our project devices can generate bioelectricity, we can also help co-supply electricity with electric power companies in those regions.
What is the coolest thing about your project?
Oliver Hernandez:
The coolest thing about our project is that we can give plastic waste management a purpose that goes further than reducing pollution. Most plastics can’t be recycled more than twice, therefore recycling doesn’t prevent plastic waste accumulation; it just delays it. Furthermore, countries that have the highest rates of plastic pollution don’t necessarily produce it, they just don’t have sufficient infrastructure to deal with the waste. The resources required to establish proper plastic waste management procedures can be perceived as a barrier for governments and companies. However, being able to use plastic pollution to solve other problems can act as the incentive needed to get these schemes going.
Another important thing to mention is that this plastic waste is being used to alleviate one of the most pressing long-term crises humanity faces: the global water crisis. Freshwater is not equally spread throughout the world, and the growing demand for freshwater in sectors such as agriculture are starting to threaten freshwater access for entire cities. Although the responsible use of freshwater is essential, a long-term solution to this increasing demand is the development of affordable and sustainable desalination techniques. The problem with desalination is that the electricity cost required by current procedures, such as reverse osmosis, are too expensive, and are not economically feasible if compared to the average price of freshwater. However, if we are able to decrease costs by alleviating electricity demand through our synthetic biological system, even in areas where the price of water must be very low to be affordable, we might be able to help desalination procedures pay off.
What kinds of challenges are you facing?
Juliette Champaud:
Like other projects, specifically in the context of a pandemic, we are facing the challenges of working remotely as a team. Having never met each other in person, we have had to acquire serious organizational and project management skills. Time is always of the essence, and working as efficiently as possible has been one of the greatest challenges we have faced.
Of course, we have also come face to face with the reality of online scientific research. Without access to the lab, we cannot properly test our product. We are therefore experiencing the struggles of simulating it computationally, and searching online through the mountain of information is like looking for a needle in a haystack. Alongside our research work, our outreach activities, also done remotely, have also been challenging. We have had to find new creative ways to explain the complex concepts we are working on in an entertaining and clear manner, without seeing the faces and expressions of our audience.
Soon, we will face the challenge of putting an end to the project or at least an end to our team’s contribution, passing it on to a new group. Who knows, this might be the greatest challenge yet, with this project being our sole focus for the past 4 months and its progress bringing us great satisfaction.
What are your next steps? What do you want to achieve with your research?
Li Xu:
Due to the current pandemic situation, our findings are mainly based on in situ results including modeling, DNA, and protein structure designs. Thus, once the situation improves, our next steps will be to test our proteins in a lab environment. We will need to check if they are correctly expressed and have the functions we expect.
Ideally, we want our proteins to be able to degrade plastics to provide ‘food’ for the other types of bacteria in the cultivating system, which can eventually produce maximum electricity by desalinating as much water as possible. The ‘food’ production rate should precisely match the consumption rate to avoid accumulation or shortage, otherwise, the other types of bacteria would probably die. Overall, our next goal will be to prove that our research can effectively propose a viable way of plastic degradation coupled with the generation of fresh irrigation water.
How can scientists harness synthetic biology to meet the 2030 UN Sustainable Development Goals?
Pedro Garcia:
Science has broken down the universe into individual subjects to allow the division of labor and specialization to take effect. As a result, civilization has achieved an astonishing level of technological proficiency. Similarly, the 2030 UN Sustainable Development Goals (SDGs) have broken down global challenges into actionable targets so that the same concepts can take effect. Despite the multitude of challenges facing our world, we are in a fortunate position. Over 3.8 billion years, life has radiated out into a wide spectrum of niches, requiring an even wider spectrum of biological technologies. From the recently discovered plastic-degrading enzymes to electricity-producing bacteria and even the potential of using DNA for computing, we have at our fingertips the ingredients for solutions to global challenges. Through synthetic biology, scientists can build on the fundamental research that has led to these discoveries by implementing the design-build-test — learn cycle to create new biological technologies. This iterative process has the potential to revolutionize areas as diverse as healthcare, energy development, and pollution remediation, similarly to how software development has done. However, through conversation with the United Nations SDG advocate Marc Buckley, it has been made clear that scientists must proceed with these ambitions with caution. The interplay between the SDGs is not to be underestimated, and without a holistic approach, scientists risk doing more harm than good. To avoid this, we must thoroughly consider the unwanted effects of our efforts.
What actions can other iGEM teams take this year in order to achieve some of the SDGs?
Laide Ibiyemi:
Scientific innovation plays a crucial role in the achievement of the SDGs. Rapid scientific development can be attained by establishing an open and collaborative community which is, fortunately, the framework iGEM is built on. With the structure of the competition, most teams are already focusing on some SDGs. However, to facilitate sustainable development, we should evaluate the impact of our projects across all the SDGs to ensure that we do not create problems in other areas while focusing on achieving a particular SDG. As a result, the cumulative impact of these efforts can lead to significant change over time.
Another vital action teams can take to achieve a transformative impact is effectively collaborating with other teams — in the past, present, and future. Build upon the work done by previous teams and share your findings comprehensively so future teams can expand on your work. Digitalization has enabled us to collaborate without geographical limitations, therefore we should make use of this opportunity to include diverse perspectives in our projects. In this way, we can develop creative solutions at an accelerated pace to accomplish the SDGs by 2030.
Note: Follow their progress on Instagram and Twitter. Learn more about how to join the iGEM program on JOGL, check out the video below.
