Yeast-Engineered Cookies Made from Plastic Bottles Could Feed Astronauts and Disaster Survivors
Scientists at Southern Illinois University Carbondale, funded by NASA, have programmed yeast to convert PET plastic and agricultural waste into protein-rich cookies called µBites.
A proprietary process called oxidative hydrothermal dissolution breaks down plastic and biomass into fragments that engineered yeasts can reassemble into proteins, fats, vitamins, and flavourings.
The technology addresses two crises simultaneously: plastic pollution and food insecurity, with potential applications ranging from deep-space missions to disaster-zone relief.
Turning Plastic Carbon into Food Carbon
The premise is deceptively simple. Plastic is carbon. Food is carbon. The question, as Lahiru Jayakody, an associate professor at Southern Illinois University (SIU) Carbondale, framed it, was whether microbes could bridge the two. Working under a grant from the NASA Deep Space Food Challenge, his team set out to answer that question by programming a variety of yeasts, including baker's yeast, to convert polyethylene terephthalate (PET), the polymer used in soda and water bottles, into edible ingredients.
PET is one of the most widely produced plastics in the world. Derived from petroleum, plastic takes between 20 and 500 years to break down naturally and already accounts for 3.4% of global greenhouse gas emissions, a figure projected to climb as production is expected to triple by 2060. The SIU Carbondale team's approach treats this waste stream not as a disposal problem but as a carbon feedstock.
The Science Behind µBites
The conversion process begins with a proprietary method called oxidative hydrothermal dissolution, developed by SIU Carbondale geology professor Ken Anderson. The technique uses water and oxygen at high temperature and pressure to break down PET plastic, discarded corn stalks, leaves, and other agricultural biomass into smaller molecular fragments that microbes can process.
These fragments are then fed to specially engineered yeasts, which reassemble them into proteins, fats, and acids, the fundamental building blocks of food. Fibre, starch, and sweeteners are added to the resulting mixture, which is then extruded through a 3D printer to produce the finished product: µBites, pronounced "microbites."
The researchers also demonstrated that the yeast platform can produce more sophisticated food additives. One engineered strain can generate vanilla flavouring from plant biomass; another converts ethylene glycol, a compound found in PET, into beta-carotene, which the human body converts into vitamin A. Graduate student Sandhya Jayasekara led this strand of the work, describing the goal as making µBites a more consumer-friendly product.
Safety testing indicates the plastic-derived cookies are safe to eat, though the team is still awaiting institutional approval to conduct formal taste tests. Preliminary aroma assessments have been broadly positive, with most participants indicating they would eat µBites in resource-limited situations.
From Deep Space to Disaster Zones
The NASA Deep Space Food Challenge, which funded this research, specifically targets food systems for long-duration missions where resupply is impossible. The SIU Carbondale team positions µBites as a candidate for exactly those conditions: deep-space missions, lunar or Martian colonies, submarines, and disaster-zone relief operations where conventional supply chains have broken down.
The broader food security argument is equally striking. Jayakody cited projections suggesting global food demand will rise 35 to 56% by 2050, with roughly 30% of the world population at risk of hunger. The ability to convert widely available plastic and agricultural side-streams into nutrition could, in principle, offer one avenue for addressing that gap, particularly in regions where conventional agriculture is failing.
Limitations and What Comes Next
Several hurdles remain. The current production cost of $60 per kilogram is high, though the team argues that improving yeast efficiency and scaling up production will bring this down. Formal human taste trials have not yet been conducted, meaning palatability at scale is unproven. The scientists also intend to replace the externally sourced starch, fibre, and sweetener components with microbially produced alternatives, a step that would be necessary for truly closed-loop, resource-independent production.
The timeline for public consumption remains optimistic but vague: the team hopes the product could be ready within a few years. Whether that translates into a commercially viable food ingredient or remains a niche solution for extreme environments will depend on regulatory approvals, cost reduction, and, ultimately, whether consumers are willing to eat a cookie whose carbon once held a soft drink.
