Team:UCL/Sustainable

Team:UCL/Page Name - 2020.igem.org

Overview

Part 1: Description

Overconsumption of plastic is placing ever-increasing burdens on delicate ecosystems. Estimates show that by 2050, CO2 emissions from plastic overconsumption could reach 10-13% of the entire remaining CO2 budget that is available to keep global temperature rise under 1.5°C [1]. Researching this issue led us to another global challenge: freshwater scarcity. According to the UN, 1.2 billion people live in regions suffering from freshwater scarcity [2] with climate change threatening to exacerbate this.

Considering that the earth contains enough freshwater to sustain over 7 billion people [2] and that current seawater desalination methods are highly energy intensive, innovation in freshwater production methods is desperately needed. To this aim, our research project employed in silico modelling to investigate the potential of using synthetic biology to integrate enzymatic polyethylene terephthalate (PET) degradation with Microbial Desalination Cell (MDC) technology.

As described in the Global Sustainable Development Report, to achieve the SDGs by 2030 our world must go from merely improving the methods by which we target the SDGs to transforming these methods instead. One of the most important concepts promoted by the report that can accelerate this transformation is the circularisation of economies. Using in silico modelling, we have shown that synthetic biology is a vital tool for transforming the strategies we use for targeting the SDGs. By creating a solution to PET pollution and freshwater scarcity, we have made steps towards circularising the plastics economy to turn waste into useful outcomes.

Resources mobilised

£16,000 stipend paid to our team of eight students to support our work over the 2020 summer and constant guidance from our supervisors

Part 2: SDGs & Targets

SDGs we are targeting [3] [4]

Our MDC device aims to improve this by providing a less energy-intensive alternative to methods such as reverse osmosis, so that more people around the globe can have access to clean water and sanitation. Furthermore, our device aims to reduce the amount of plastic pollution in our freshwater sources.

We aim to tackle the following specific targets:

6.1 By 2030, achieve universal and equitable access to safe and affordable drinking water for all
6.3 By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally
6.A By 2030, expand international cooperation and capacity-building support to developing countries in water- and sanitation-related activities and programmes, including water harvesting, desalination, water efficiency, wastewater treatment, recycling and reuse technologies

Our MDC device promotes technology that makes good use of discarded PET plastics, with the desalinated water.

We aim to tackle the following specific targets:

12.4 By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water and soil in order to minimize their adverse impacts on human health and the environment
12.5 By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse
12.A Support developing countries to strengthen their scientific and technological capacity to move towards more sustainable patterns of consumption and production

Our MDC device aims to alleviate the damages caused to underwater ecosystems by degrading polluting PET plastics.

We aim to tackle the following specific target:

14.1 By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution

Our MDC device aims to alleviate the damages caused to underwater ecosystems by degrading polluting PET plastics. Our provision of desalinated water can aid desertification, land degradation and biodiversity loss.

We aim to tackle the following specific targets:

15.3 By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world

Targets of the project

Our overall goal was to tackle plastic pollution and freshwater scarcity using synthetic biology. To achieve this, we broke our project down into four individual objectives:

Use genetic engineering to express enzymatic PET degradation pathway in E. coli and P. putida
Achieving a successful co-culture of the above bacteria along with S. oneidensis
Constructing and operating an MDC to desalinate seawater
Engaging with key stakeholders and experts for successful implementation

Part 3: Project Development

Timeline & deliverables

Over the course of 6 months, our team of students focused on the following deliverables to achieve the individual target:

Conduct in vivo experimental techniques to measure the activity of our PETase enzymes
Perform in silico Flux Balance Analysis (FBA) modelling to test the viability of our bacterial co-culture
Perform in silico Cellular Automata (CA) modelling to test the seawater desalination rate of our MDC
Distribute a research survey to measure key stakeholders’ opinions and receive feedback from experts on our proposed implementation strategy

For more information, please visit our Engineering, Model, and Implementation page.

Key stakeholders and partnerships

Our team conducted an analysis into the regions that were simultaneously suffering from plastic pollution and freshwater scarcity. This analysis found that there were between 10-20 countries around the world that were significantly affected by these two issues, with our main target identified as Ghana. For the purposes of our project, the key stakeholders are entire populations of people that live in these multiple affected areas, as well as any populations of people that live in areas affected by one of the individual challenges.

To benefit our key stakeholders with our proposed microbial desalination cell technology, we partnered with two other iGEM teams from Exeter University from the UK and from Ashesi University from Ghana to improve our synthetic biology and human practices approaches, respectively.

Positive SDG interactions

The underlying principles of the Sustainable Development Goals to systematically tackle global issues, has led to them being interconnected by design [5]. This philosophy lies at the core of our project and has guided us throughout the development process. The idea for one incorporated technology that attempts to alleviate plastic pollution and water scarcity attests to this alignment of ideals. The interactions between goals are scored on a scale between +3 to –3, with the positive interactions being +3 indivisible, +2 reinforcing and +1 enabling. We have developed our idea in such a fashion, that aims to integrate our targeted SDGs in the strongest manner.

Utilising PET waste as the energy resource for PET-digesting microbes in our device represents our alignment with SDG 12 and the sustainable incorporation of used and discarded PET plastics into the water-treatment infrastructure. In turn, our Synthetic Biology-driven proposal to desalinate water via electricity generated by microbes, dependent on PET metabolites as their food source integrates SDG 12 with SDG 6, aiming to achieve both in an integrated manner (at an interaction of +3) and providing one possible sustainable solution to water scarcity. By providing a sustainable source of water, we aim to improve life on land and incorporate SDG 15 into the objectives we ourselves aim to achieve; tackling desertification along the world’s coastlines can be assisted and reinforced (with a +2 interaction) by our proposed technology.

We are conscious of the incredibly intricate sensitivity of our world’s ecosystems and have been deeply saddened by the effects of plastic pollution on the world’s oceans and the creatures living within. By tackling PET pollution, we undeniably support the achievement of SDG 14 with our technology (at an interaction of +3) and alleviate some of the harmful effects posed by plastic pollution to life below water. We aim to co-operate with ocean clean-up initiatives that conserve the oceans and utilise discarded PET plastic for sustainable development.

Negative SDGs interactions

Initial costs for the development of the infrastructure of our technology may have an environmental impact, meaning that rapid adoption of our technology may have a negative impact on SDG 13. However, methodologies exist and can be developed for the sustainable construction of such a device, which is the route we should take to avoid detrimental effects.

Another concern with our technology is that improving the state of enzymatic PET degradation may lead multinational companies to adopt the technology to produce even more PET in products such as drinks bottles. Ideally, the world should transform how we use plastic polymers and shift to ones that are more biodegradable and emit less CO2 in production. Therefore, there is a risk that our proposed MDC technology could perpetuate the demand for damaging PET plastics and cancelling out SDG 13 with an interaction of –3. Therefore, we have designed our implementation plans to avoid this possibility by targeting precise situations in which it does not perpetuate the demand for PET plastics.

Unknown. Plastic & Climate | The Hidden Costs of a Plastic Planet [Internet]. 2019 [cited 2020 Oct 25]. Available from: https://www.ciel.org/wp-content/uploads/2019/05/Plastic-and-Climate-Executive-Summary-2019.pdf
United Nations. Water scarcity [Internet]. International Decade for Action “Water for Life” 2005-2015. 2014 [cited 2020 Oct 25]. Available from: https://www.un.org/waterforlifedecade/scarcity.shtml
International Council for Science. Overview of the Sustainable Development Goals and Targets [Internet]. Paris; 2017. Available from: http://bit.ly/sdg-interactions-guide
UN Department of Economic and Social Affairs. THE 17 GOALS | Sustainable Development [Internet]. 2015. Available from: https://sdgs.un.org/goals
International Council for Science. A guide to SDG interactions: From Science to Implementation. 2017.