Scientists 3D-Printed Cookies From Plastic Bottles and Corn Stalks

From Trash to Dough

Researchers at Southern Illinois University Carbondale have built a food production system that starts with polyethylene terephthalate, the plastic in most soda and water bottles, and discarded corn stalks and leaves. The material goes through oxidative hydrothermal dissolution, a process that uses water, oxygen, heat, and pressure to break the waste into fragments microbes can consume. Engineered yeast strains then rebuild those fragments into proteins, fats, and acids.

3D Printing the Final Cookie

The resulting biomass is mixed with fiber, starch, and sweetener into a printable paste. A 3D printer extrudes it layer by layer into cookies shaped like the Greek letter mu, giving the snack its name: µBites, pronounced microbites. The team presented the prototype at the American Chemical Society Fall 2026 meeting in Chicago.

Separate yeast strains add flavor and color. Baker's yeast produces vanilla flavoring from plant biomass, while another strain converts ethylene glycol from PET into beta-carotene, the pigment that gives carrots their color and a precursor to vitamin A.

Why NASA Funded It

The project sits inside NASA's Deep Space Food Challenge, which looks for ways to feed crews on long-duration missions where resupply is impractical. A round trip to Mars could take about three years, so turning onboard waste into food is more than a curiosity: it is a logistics problem.

The researchers also frame µBites as a way to address two earthly problems at once. Global food demand is expected to rise sharply by 2050, and plastic pollution keeps accumulating. Converting waste carbon into edible protein turns disposal into production, at least in the lab.

Still a Prototype

The cookies are not ready for grocery shelves yet. The team is still waiting for institutional approval to run formal taste tests. Early aroma tests went well, and the data show the cookies are safe to eat, but the researchers still add starch, fiber, and sweetener by hand. The goal is to engineer yeasts that produce those ingredients too, making the process fully microbial within a few years.