Specialized microbes convert inedible materials into protein-rich snacks.
A cookie made partly from molecules derived from plastic waste sounds more like a warning than a food experiment. But researchers at Southern Illinois University Carbondale are using engineered yeast to transform components of discarded plastic and agricultural waste into proteins, vitamins, fats, flavorings, and other ingredients that could one day help produce food in resource-limited environments.
The approach brings together two major challenges: finding useful destinations for plastic waste and developing additional ways to produce food.
The work is part of a NASA-led project aimed at producing food for deep-space exploration, where resources are limited. The same technology could eventually have uses on Earth, including in disaster zones.
“We were trying to develop technologies for plastic upcycling to make more valuable products. We thought, why not focus on making food? Because plastic is carbon and food is carbon,” explains Associate Professor Lahiru Jayakody.
Yeast turns waste into food ingredients
The team’s prototype is a protein-rich cookie called µBites, pronounced “microbites.” Rather than putting plastic directly into food, the researchers first break waste materials into smaller chemical components that microbes can consume. Engineered yeasts then rebuild those molecules into compounds useful for food.
One target is polyethylene terephthalate, or PET, the common plastic used in many soda and water bottles. PET contains carbon-rich molecules that can be broken apart and repurposed. Instead of rebuilding them through chemical reactions and solvents in a lab, the researchers use microbes to do much of that work.
Jayakody adds, “microbes are very clever. So, we are using their traits to solve the problems we created.”
Scientists already use microbes, including yeast, as miniature factories for useful molecules. Insulin, for example, can be produced by programmed yeast rather than extracted from animal pancreases.
Jayakody and graduate student Sandhya Jayasekara applied that principle to waste. They programmed several kinds of yeast, including baker’s yeast, to transform molecules found in plastic and agricultural waste into proteins, vitamins, flavorings, and other food components.
Tough waste must be broken down first
Before the yeast can do that work, however, tough waste materials must be broken down into forms the microbes can access.
The researchers processed PET plastic, discarded corn stalks and leaves, and other biomass using a proprietary technique called oxidative hydrothermal dissolution. Developed by SIU Carbondale Geology Professor Ken Anderson, the method uses water and oxygen at high temperature and pressure to break tough materials into smaller pieces that microbes can consume.
Those breakdown products are then fed to the engineered yeasts, which convert them into ingredients including proteins, fats, and acids. The researchers currently add fiber, starch, and sweetener before extruding the mixture through a 3D printer to create µBites.
The team reports that its data show the cookies are safe to eat, although institutional approval is still pending before researchers can conduct taste tests. For now, participants have evaluated their aroma, and most said they would be willing to eat the cookies in situations where resources were limited.
Vanilla and beta-carotene improve the recipe
Making the cookies appealing to consumers under less extreme circumstances poses another challenge: flavor.
Jayasekara has engineered baker’s yeast to produce vanilla flavoring from plant biomass. Another yeast strain can convert ethylene glycol derived from PET into beta-carotene, which the body can convert into vitamin A.
“We’re using microbes to develop the cookie into a more attractive, consumer-friendly product,” says Jayasekara.
The goal extends beyond cookies
The researchers eventually want microbes to produce more of the cookie’s basic ingredients, including the starch, fiber, and sweetener that are currently added separately. Jayakody hopes µBites could be ready for public consumption within a few years.
The broader goal goes beyond cookies. Technology that turns waste into useful food ingredients could have applications in resource-limited settings on Earth and in extreme environments, including submarines and potential colonies on the moon or Mars.
“Global food demand is expected to rise 35–56% by the year 2050, and about 30% of the world population will be at risk of hunger in the future. The way to address that, I believe, is by using microbes,” he concludes.
The results were presented during the “Undergraduate and Graduate Research in Biochemistry and Chemical Biology” symposium at ACS Fall 2026, held August 23-27 at McCormick Place.
Meeting: ACS Fall 2026
The research was funded by the NASA Deep Space Food Challenge and a National Science Foundation Faculty Early Career Development Program (CAREER) grant.
Title
Engineered yeast consortia for converting plastic and biomass-derived compounds into valuable food additives
Abstract
With billions of people experiencing hunger in 2025 and unable to afford a healthy diet, food insecurity remains a critical global challenge. “µBites,” originally developed for the NASA Deep Space Food Challenge, represents a novel way of producing nutritious food by converting plastic and plant waste into edible, protein-rich supplements. Beyond space travel, µBites could offer a promising solution to address both food shortage and plastic pollution simultaneously. We have previously demonstrated the successful 3D printing of edible, µBites protein cookies using plastic-derived substrates and yeast biomass. In this study, we demonstrate the enhancement of flavor, aroma, and color of these cookies using naturally produced ingredients by safe-to-eat yeast strains, Saccharomyces boulardii, S. cerevisiae, and Rhodosporidium toruloides. We engineered S. cerevisiae to produce vanillin, the compound that is responsible for vanilla flavor and aroma, from ferulic acid. Adaptive laboratory evolution of R. toruloides enhanced its utilization of ethylene glycol as a carbon source to produce β-carotene, a vitamin A precursor. We demonstrated the production of these ingredients from waste biomass and plastic-derived substrates, combined with the yeast-derived protein to produce nutritionally enhanced 3D-printed “µBites.” This project’s outcomes will revolutionize the production of next-generation microbially derived food ingredients from waste organic carbon, contributing to a circular economy of plastics.
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1 Comment
I admit that I haven’t read this article ( I just read the first few paragraphs). BUT the very idea of eating ANYTHING derived from plastic (especially waste plastic) is utterly revolting. No, absolutely NO !
The energy industry must be getting really desperate to sell their global-warming oil ! ! !