Researchers at Southern Illinois University (SIU) Carbondale have developed a novel method to turn discarded plastic and farm waste into edible, disc-shaped snacks called μBites. The research began as part of NASA’s Deep Space Food Challenge, which invited scientists to design food technologies for long-duration space missions. The team presented its findings at a meeting of the American Chemical Society in Chicago.
Transforming Trash Into Treats Through Microbial Engineering
“My lab works on developing technologies for plastic upcycling,” said Dr. Lahiru Jayakody, a microbiologist who led the project. “We thought, why not look into food? Plastic is carbon and food is carbon.”
From Recycled Bottles to Cultured Slurry
The transformation process starts with polyethylene terephthalate (PET), a common material used in single-use water and soda bottles. The team uses an SIU-developed technique called oxidative hydrothermal dissolution, which applies oxygen and water under intense heat and high pressure to break the tough plastic down into smaller carbon-rich molecules.
This plastic material is combined with agricultural waste, such as corn stalks and leaves, to produce a liquid feedstock. Cultured yeast is then fed this mixture. The genetically reprogrammed microbes convert the carbon into biological molecules, including proteins, fats, and other nutrients, resulting in a nutritious food slurry that serves as cookie dough starter. Additionally, researchers engineered different yeast strains to produce specific compounds:
- One strain produces vanillin to provide a vanilla scent and flavor.
- Another strain creates beta-carotene, an orange pigment that the human body converts into vitamin A.
- The resulting dough mixture is ultimately passed through a 3D printer to form the finished disc-shaped cookie.
Current Hurdles and Production Costs
In its current state, the system can convert over 50 percent of the carbon from waste materials into food products within a day or two. The team eventually aims to recirculate unconverted carbon to achieve near 100 percent conversion, noting that roughly 10 percent of carbon material currently escapes as waste gas or remains unconverted.
Production costs currently stand at $60 a kilogram, though researchers expect that improving yeast efficiency and scaling up operations will reduce expenses over time. Before human consumption can begin, the team must secure formal clearance.
“We haven’t eaten them yet because we’re awaiting approval for testing in humans,” Jayakody said, noting that the snacks have nonetheless received high marks for their aroma.
Potential Applications in Space and Disaster Zones
Beyond deep-space exploration—such as three-year round-trip missions to Mars where crews must utilize all available resources—the team suggests the technology could support extreme environments on Earth, including submarines or disaster zones.
Project leaders also frame the concept as a potential response to broader ecological and demographic pressures. Global food demand is projected to rise between 35 percent and 56 percent by the year 2050, while approximately 30 percent of the world population may face future hunger risks.
“The way to address that, I believe, is by using microbes,” Jayakody said, though the team acknowledges that public acceptance of plastic-derived food remains a hurdle to clear.
