Project Description

Choosing Our Project

When deciding the topic for our iGEM 2022 project, we considered how we could best use synthetic biology to solve global environmental issues. Additionally, we wanted to build on similar efforts, so we researched previous iGEM projects using iGEM’s Project Phoenix [1] software. We examined these projects and their wikis before selecting three topics that we believed could be best addressed with synthetic biology: combating antibiotic resistance, fighting red tides, and degrading polychlorinated biphenyls (PCBs). Our team struggled to choose one topic, so we split into smaller groups to further research and present our findings to the entire team. We used scientific literature to better understand the feasibility and relevance of each topic. After much debate and several close votes, we decided to pursue a project on PCB detection and degradation. We thought this topic is closely connected to our geographical locations and combined feasibility and ambition. Our team, although located in New York and Baltimore, shared proximity to major waterways: the Hudson River and the Chesapeake Bay. The relevance of PCB caused our team to quickly become interested to learn more about PCB pollution. Despite the prohibition on the usage of PCBs decades ago, these two waterways are polluted by over a million tons of PCBs. Therefore, we chose to investigate the degradation of PCBs for our iGEM project.

PCBs

Our research shows that exposure to PCBs is harmful to humans and ecosystems. Since these chemicals are man-made, the environment is unequipped to combat them. Some current solutions for PCB removal include land burial and incineration, which are harmful to the environment. Land burial only displaces PCBs instead of removing the contamination, and burning PCBs create more harmful chemicals like polychlorinated dibenzodioxins and polychlorinated dibenzofurans that are also associated with cancer.

In terms of detecting PCBs, Surface Enhanced Raman Spectroscopy (SERS), Surface Plasmon Resonance (SPR), electrochemical impediment sensors, whole-cell sensors, gas chromatography, and microflow chips are technologies currently used to detect PCBs; however, they are all expensive, and many are found only in well-equipped labs.

Our Project

Due to the need for a sustainable, safe, and cheap solution for the detection and degradation of PCBs, our project is a relevant application of synthetic biology. If a synthetic biology solution becomes available, other harmful solutions will not be employed. This means that smaller nonprofits would have open access to a secure technique to help underprivileged communities affected by PCB contamination. Clearly, out of all the possible solutions, synthetic biology is the safest as it involves neither the transportation nor the creation of toxic chemicals and, if administered properly, will not harm any ecosystems.

The two main goals of this project are

1. to develop a biological sensor to detect PCBs
2. to degrade PCBs into less harmful chemicals

Inspirations

Our work was inspired by research from two previous iGEM teams: Stockholm and Chalmers-Gothenburg. The Stockholm 2022 team tried to develop a contaminant sensor for waterways, which inspired our biomodular PCB sensor. The Chalmers-Gothenburg 2019 Project took genes from multiple bacteria and inserted them into yeast. However, many of the genes were not successfully integrated and expressed. We wish to apply the concepts they used but take the project further than they did. Locally, the Baltimore National Aquarium and other groups in the Inner Harbor have conducted tests and proposed solutions to PCB contamination. The Magothy River Association in New York has also run similar experiments concerning solutions to PCB contamination. Our hope is that our project builds on these projects, providing a bacterial degradation and biosensor that sustainably and effectively mitigates the threat of PCBs.