UI students are rewiring genes to create biodegradable plastic

University of Iowa students from a handful of disciplines are competing in an international genetic engineering competition. — illustration by Jordan Sellergren

Genetic engineering has long been the poster child of science fiction. In Frank Herbert’s series Dune (1965-85), human bloodlines and selective breeding programs are implemented to produce an optimal species. The release of Gattaca in 1997 heralded a wave of terror over genetic engineering and designer babies free of disease. For decades, these stories were discarded as the outlandish ruminations of science fiction writers.

Today, genetic engineering is a reality. In countless laboratories around the world, mice are genetically modified to study disease, cells are altered to secrete therapeutic proteins (such as E. coli producing much of the world’s insulin supply) and crops are optimized to withstand drought. In August, scientists reported that they had successfully removed a gene from human embryos that causes heart disease later in life. But despite genetic engineering’s considerable media attention in recent years, its story remains, in Iowa, one of new beginnings.

Jan Fassler, a professor of biology at the University of Iowa, has sought to bring the young field of synthetic biology to Iowa City for years. Through synthetic biology scientists attempt to reliably program and engineer living organisms using genetic modifications. Within the last decade, bacterial cells have been engineered to perform numerical calculations, store memory (in much the same way that a computer does), detect tumors and even digest plastic and secrete the fragments as carbon dioxide.

This year, Fassler is mentoring the first synthetic biology research team at the University of Iowa. The team is participating in the International Genetically Engineered Machine (iGEM) competition, which began as a one-month course at MIT 14 years ago and is now an expansive contest with over 300 participating teams worldwide. Past student projects include water-testing bacteria that change color in response to arsenic, mats of bacteria that function as photographic film when exposed to a flash of light and modified bacteria that produce complex drugs. Teams work on their projects from June to October — with such a brief time to complete an intensive research project, many students work full-time throughout the summer to engineer their bacteria and collect results.

Drawing together a dozen students from biomedical engineering, biochemistry, chemistry, ethics and business, the Iowa iGEM team works in an unused training laboratory in the Biology Building. Their lab space is fully equipped with freezers, bacterial incubators and centrifuges. The interdisciplinary nature of the team is intentional; the competition requires that students report on the ethics of their research, engage with the community about the benefits of synthetic biology and build a website from scratch so that anybody can view their results online. Fassler said she was excited to see a team materialize on campus and impressed by the breadth of students involved.

“One of the goals of the … competition is to attract new talent to the field by making it clear that anyone with an imagination, a willingness to troubleshoot and a sense of community can participate,” she said. “In my opinion, the field of synthetic biology is the ultimate STEM recruiting device.”

Fassler became interested in the iGEM concept several years ago while teaching a genomics course to undergraduates. It was there that she introduced students to the competition and the idea of a biological discipline with roots in engineering.

Through synthetic biology, DNA instructions are taken out of their original contexts and placed into a catalog, organized by potential uses, Fassler said. Bioengineers can then use that catalog, “string together off-the-shelf DNA components” and insert those strings into organisms to perform various tasks.

Each iGEM team can order DNA sequences from a facility in Boston. Once those sequences arrive in test tubes, students piece them together and insert the combined DNA sequences into cells. Teams also have the option to submit their own original sequences to the facility, which are stored so that future teams can use them. Every DNA sequence that has been submitted in previous years is listed in the catalog, known as the Registry of Standard Biological Parts.

For their inaugural project, the Iowa iGEM team is hoping to improve the way that plastics are produced and degraded. They are developing engineered microbes that can help manufacture biodegradable, green plastics using a molecule called 3-hydroxypropionate (3HP). Microorganisms naturally produce 3HP molecules, which can be linked together to create a biodegradable plastic called poly-3HP, which degrades quickly in the environment, releasing water and carbon dioxide as it breaks down.

Current technologies to manufacture 3HP, however, are more expensive than competing, non-degradable plastics, such as PET. There are several companies today that use engineered microorganisms to produce 3HP, but technologies to detect the molecule are limited. In an effort to lower the cost associated with producing the molecule, the Iowa iGEM team is engineering bacteria to sense 3HP and produce light in response. The team hopes that industrial plastic manufacturers will utilize their technology to quickly test and scale 3HP manufacturing processes.

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Mason Lamarche, a fourth-year biomedical sciences major, is one of the team members.

“I joined Iowa iGEM to work in a collaborative setting with other talented undergraduates on a project that we could really claim as our own. By developing a 3HP detection system, we are working on biological and industrial problems with a real-world impact,” Lamarche said.

The team and Fassler are not alone in their research endeavors. The students also receive mentoring from Edward Sander and Craig Ellermeier, faculty members in the biomedical engineering and microbiology departments. Sander, an expert on tissue engineering, noted the potential of synthetic biology to solve a wide range of problems in the manufacturing, industrial, chemical and biomedical fields.

“Perhaps what is most exciting is the avenue it provides to understand how life works,” Sander said.

Ellermeier, a microbiologist and immunologist, studies how bacterial cells sense and respond to signals in their environment. He said that although UI undergraduates have many research opportunities, iGEM is unique in that it “provides students the opportunity to compete with other teams in developing a synthetic biology project while at the same time contributing to the development of open source biological parts that can be used by others.”

On Nov. 9, the team will present their findings at the iGEM Jamboree in Boston. Teams present their work in front of thousands of attendees and, at the end of the event, winners are selected from a variety of categories, including a grand prize for the top overall project, the best team website and the most impactful community outreach initiative.

To ensure that the field of synthetic biology continues to bloom in Iowa, Fassler, Sander and Ellermeier developed a lab-based course in synthetic biology, which will be open to undergraduate students next summer. While slow to materialize, it certainly seems that the creative visions of science fiction writers are here to stay in Iowa City.

Nicholas McCarty is the co-founder of the Iowa iGEM synthetic biology team and a current student at Imperial College London. This article was originally published in Little Village issue 231.