Plastic bottles might sound like the last thing anyone would want near their food.
But scientists are developing a surprising technology that uses engineered yeast to transform components of plastic and agricultural waste into edible ingredients.
Researchers at Southern Illinois University Carbondale have programmed different types of yeast to convert waste materials into proteins, vitamins, fats and flavoring molecules.
These ingredients can then be used to make protein-rich cookies called µBites, or “microbites.”
The research was presented at ACS Fall 2026, a meeting of the American Chemical Society.
The work is part of a NASA-led project exploring ways to produce food in places where resources are extremely limited, including future deep-space missions.
The basic idea comes from something plastic and food have in common: carbon.
One of the world’s most common plastics is polyethylene terephthalate, or PET, which is widely used for water and soft drink bottles.
PET contains carbon-rich molecules. Instead of simply throwing this carbon away, the researchers wondered whether microbes could transform it into something useful.
Microorganisms such as yeast are already widely used as tiny biological factories. Scientists can program them to produce valuable substances, including medicines and food ingredients.
The researchers applied the same idea to waste.
First, PET plastic, discarded corn stalks and leaves, and other plant material are broken down using a process called oxidative hydrothermal dissolution. The method uses water and oxygen under high temperatures and pressures to break tough waste into smaller molecules that microbes can process more easily.
These molecules are then fed to specially programmed yeasts, including baker’s yeast. The microbes convert them into useful food components such as proteins, fats and acids.
Researchers combine these ingredients with fiber, starch and sweetener. The mixture is then passed through a 3D printer to create the protein-rich µBites cookies.
The researchers say their data indicate that the cookies are safe to eat, although they are still waiting for institutional approval before conducting human taste tests. So far, people have been allowed to smell the cookies, and many participants said they would consider eating them if food supplies were limited.
The team is also working to make the cookies more nutritious and appealing. Researchers have engineered baker’s yeast to produce vanilla flavoring from plant material. Another type of yeast can transform ethylene glycol, a chemical that can come from breaking down PET, into beta-carotene. The human body can convert beta-carotene into vitamin A.
Eventually, the scientists hope microbes will also produce the starch, fiber and sweeteners currently added separately to the cookies.
The technology could have uses far beyond space travel. Systems capable of turning local waste into food could potentially provide emergency nutrition after natural disasters or in other places where normal food supplies are difficult to obtain.
Researchers hope µBites could be ready for public consumption within a few years. In the longer term, similar technology might provide food in submarines, remote locations or even future settlements on the moon and Mars.
With global food demand expected to rise substantially by 2050, the researchers believe microbes could offer an unusual way to tackle two major problems at once: growing amounts of waste and the need to produce more food.
