Transforming Plastic Waste into Edible Snacks
Could a plastic bottle be turned into a biscuit? This intriguing question has been raised by researchers at Southern Illinois University (SIU) Carbondale, who are pursuing an innovative and potentially groundbreaking project: converting agricultural and plastic waste into edible ingredients. Their approach utilises microorganisms, such as bread yeast, to achieve this remarkable feat. So far, they have developed a snack called µBites (pronounced “microbaits”), which are protein-rich biscuits that could serve a crucial role both on Earth and in environments where food is scarce, such as deep space or even certain parts of the planet by mid-century.
The initiative is part of NASA’s Deep Space Food Challenge, which aims to develop creative recycling technologies for plastics, ultimately producing more valuable products. Dr. Lahiru Jayakody, a microbiology researcher at SIU Carbondale, explains, “We thought, why not focus on food production? Plastic is carbon, and so are food products.” This insight has driven their exploration into the potential of transforming plastic into consumables.
Utilising PET for Food Production
One of the primary materials under investigation is polyethylene terephthalate (PET), the notorious plastic used to manufacture millions of water and soft drink bottles each year. The idea of consuming PET may seem far-fetched; however, humans are already ingesting alarming amounts of microplastics. The researchers aim to add a crucial step in the process to ensure that plastic does not harm us. Instead of relying on chemical methods to convert plastic waste into food, they are utilising genetically modified microorganisms to harness the molecules within. “Microbes are incredibly intelligent,” remarked Professor Jayakody. “We are leveraging their capabilities to address problems we have created ourselves.”
The Innovative Process Behind µBites
The initial step involves the hydrothermal oxidative dissolution of PET, along with corn plant waste and other biomass. This method, developed by Ken Anderson, a geology professor at SIU Carbondale, uses water and oxygen at high temperatures and pressures to break down tough materials into compounds that microorganisms can utilise. Subsequently, various yeast strains come into play. The researchers, including Jayakody and graduate student Sandhya Jayasekara, programme these microorganisms to convert waste-derived compounds into new ingredients, similar to how yeast is genetically modified to produce insulin. The yeast can generate proteins, fats, and acids, as well as compounds designed to enhance food characteristics.
The strategy draws on decades of scientific understanding, employing microorganisms as tiny biological factories capable of producing specific molecules. The yeast strains used in this research include Saccharomyces boulardii, S. cerevisiae, and Rhodosporidium toruloides.
Creating a Biscuit from Waste
Once the ingredients are obtained, the team adds fibre, starch, and a sweetener, before extruding the mixture through a 3D printer to form the µBites. Initial results indicate that these biscuits are safe for consumption, although the researchers are still awaiting institutional approval for taste testing. So far, sensory evaluations of the aroma have been positive, with most participants expressing a willingness to consume the biscuits in resource-limited situations.
Aiming for Broader Appeal
The next challenge is to make these biscuits appealing beyond extreme circumstances. To achieve this, Jayasekara has developed yeast strains capable of producing compounds that enhance flavour, aroma, and nutritional value. One strain of bread yeast can generate vanillin from plant biomass, while another has been engineered to utilise ethylene glycol from PET to produce beta-carotene, a compound that the body can convert into vitamin A. “We are using microbes to transform the biscuit into a more attractive and palatable product,” stated Jayasekara.
Future Prospects in Food Sustainability
The ultimate goal is to produce even more components of the µBites—such as starch, fibre, and sweeteners—through microorganisms. Given the abundance of plastic waste in the world, there is significant potential for creating sustainable snacks indefinitely. The team hopes to bring these biscuits to the public in the coming years.
As global food demand is projected to increase by 35% to 56% by 2050, with around 30% of the population potentially facing hunger, Jayakody believes that the solution lies in the utilisation of microbes. Addressing the global food crisis, the plastic pollution dilemma, and creating delicious snacks all at once—what could be better than that? This innovative research was showcased at the ACS Fall 2026 event, organised by the American Chemical Society (ACS) from August 23 to 27 in Chicago.