Pauline Ostoja-Starzewski is one of five undergraduates from the University of Illinois at Urbana-Champaign taking part in the International Genetically Engineered Machine Competition (iGEM) this summer. Here, she introduces iGEM, and her team’s project to break down excess herbicides in the environment. 

Each spring, academic institutions around the globe start gathering their resources and interviewing potential candidates for their team. There are three levels of iGEM teams, including graduate, undergraduate, and high school-level teams. After each institution finalizes their team members, the multi-disciplinary students are tasked with developing a unique project idea that utilizes genetic engineering to solve modern-day problems. 

With 353 teams registered for this year alone, coming up with a novel idea can be quite a challenge. Additionally, the list of requirements found on the iGEM website requires students to work both inside and outside the lab. Various tasks can be checked off as teams complete the bronze, silver, and gold medal requirements. Ultimately, all of this work leads up to the Giant Jamboree, held in Boston every fall. This year, five of UIUC’s undergraduate students will be attending the five-day conference at the Hynes Convention Center to defend their work and compete for the gold medal.

The UIUC iGEM team was created thanks to funding by the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) and the Carl R. Woese Institute for Genomic Biology (IGB). Our varied backgrounds have allowed us to collaborate in ways that play to everybody’s strengths. Sachin Jajoo, 19, and Pauline Ostoja-Starzewski, 21, are majoring in Molecular and Cellular Biology. On top of this, Ally Choi, 21, is majoring in Biochemistry, and Jennifer Ward, 22, is majoring in Chemical Engineering. Finally, Sophie Liu, 20, is majoring in Materials Science and Engineering. 

Together, the five of us wanted to come up with a project that incorporates synthetic biology in a way that can benefit public health and the environment. Guidance from principal investigator Chris Rao helped us zone in on plant biology. After weeks of finalizing a plan, we decided to genetically engineer Escherichia coli to include the glyphosate degradation pathway naturally found in Bacillus subtilis, a common soil bacterium.

Glyphosate, a herbicide, is widely used in the United States due to its ability to kill a broad spectrum of weeds that threaten crops such as corn, wheat, and soybeans. It is also the primary ingredient in Monsanto’s Roundup. Following the recent lawsuits surrounding Roundup and its carcinogenic properties, we figured glyphosate was something worth looking into. Of course, the opinions on the matter are very polarized. While some claim it is a carcinogen, others believe it to be a vital and harmless part of today’s farming methods. Although Monsanto claims that glyphosate degrades in the soil in a matter of days, it has also been known to persist above safe levels for quite some time now. Knowing all this, we decided to spend our summer working on engineering E. coli in such a way that it can later be administered to bodies of water that have surpassed safe glyphosate levels.

Growth curve for E. coli in glyphosate.

As with any project, the first step in minimizing the glyphosate footprint of Roundup on the environment was to do some research on the topic. Following an intensive period of literature review, it became clear that this is still a relatively new field of research.

Thus, we decided to turn to experts here at the University of Illinois, specifically those who specialize in crop sciences. Following a series of interviews, the general consensus was that glyphosate is commonly used because it works, it’s easy, and it’s economically beneficial. The reason why organic crops have become so rare in the United States is a direct result of this phenomenon. Organic farming requires a lot of time, effort, and money to maintain non-glyphosate fields. Monsanto has therefore had a huge impact on the high crop yield of this country. 

However, over the years, these plants have started developing genetic resistance to glyphosate. Associate Head of Crop Sciences, Patrick Tranel, states that “30-75% of the fields have some sort of resistance to glyphosate.” Despite this, glyphosate is still being widely used because, well, it works. Aaron Hager, Associate Professor of Crop Sciences, adds that glyphosate “will be dominant until something easier comes along, or until it is ‘broken.’” 

Knowing all of this, we as a team were still interested in glyphosate’s persistence in the environment. Research hydrologist William Battaglin from the United States Geological Survey addressed the inconsistencies regarding glyphosate mobility in soil, stating that “the half-life can vary anywhere from two days to 20 years, depending on the site.” He also added that glyphosate is detected in 59% of 470 surface water sites, and only in 8.4% of 820 groundwater sites. Now, as summer winds down and fall approaches, our UIUC iGEM hopes our strain of E. coli may someday be used to degrade leftover glyphosate in the environment.

Disclaimer: The editor is employed by the IGB as a research fellow