Researchers at Southern Illinois University have engineered microbes that can break down discarded plastic bottles and crop waste and turn them into protein-rich cookies, a step-by-step biological transformation that could address problems with plastic pollution, a looming global food crisis and help sustain deep-space missions with humans aboard.

Southern Illinois University Carbondale researchers have created what they call “ µBites ,” or protein-rich cookies with core ingredients that began as discarded PET plastic, the same material used in soda bottles, water bottles and leftover corn stalks and leaves.

The work, conducted as part of a NASA-led project aimed at creating food for deep-space exploration, uses water and oxygen under extreme heat and pressure to break tough plastic and biomass into bite-sized pieces that can be processed by microbes.

Programmed yeasts then reassemble those fragments into proteins, fats and acids, and a 3D printer extrudes the final mixture into cookie form.

Flavor is added via baker's yeast engineered to generate vanilla flavoring directly from plant biomass and a separate yeast strain converts ethylene glycol, a molecule found in PET plastic, into beta-carotene, a precursor the body transforms into vitamin A, according to the research team.

Safety testing has cleared µBites for consumption, but the team is still awaiting institutional sign-off before conducting formal taste tests.

Smell tests already conducted found most participants said they would eat the cookies in a resource-limited setting, the researchers said.

More developments. Researcher Lahiru Jayakody said the team wants to add starch, fiber and sweetener to the cookies, which he said he hopes will be ready for public consumption within a few years.

Humans have relied on microbes for thousands of years through traditional fermentation to transform raw ingredients into stable foods like bread, cheese and yogurt, but modern biotechnology allows for the genetic engineering of micro-organisms to convert inorganic materials or waste into highly nutritious compounds. By upcycling carbon waste directly into nutrient-dense, 3D-printed foods like "µBites," the researchers are offering a sustainable, closed-loop alternative to traditional farming. In theory, the new technology can alleviate severe food shortages during humanitarian crises, supply resource-limited environments like space missions and drastically cut plastic pollution. An estimated 2.1 billion people experience food insecurity worldwide and 645 million face chronic hunger, according to the United Nations, and projections indicate global food demand is on track to surge, putting nearly 30% of the world’s population at risk of hunger by 2050.

"Microbes are very clever. So, we are using their traits to solve the problems we created,” Jayakody said in a release about the team’s work.