SIU microbes convert plastic waste into protein-rich cookies

What Happened

Researchers at Southern Illinois University Carbondale (SIU) have developed a microbial upcycling approach that uses genetically programmed yeasts to convert plastic-derived molecules and agricultural waste into edible proteins, vitamins and flavouring compounds. The team processed PET plastic, discarded corn stalks and leaves, and other biomass using an in-house method called oxidative hydrothermal dissolution. The programmed yeasts then metabolized these components to produce ingredients suited for a protein-rich cookie concept named µBites, which are formed by combining the ingredients with fibre, starch and a sweetener and extruding them through a 3D printer. The cookies are described as safe to eat based on available data, though institutional approval for taste testing is pending. The work is part of a NASA-led project focused on food technologies for deep-space missions, and the team plans to present their findings at the American Chemical Society’s Fall 2026 meeting in Chicago. PI Lahiru Jayakody and graduate student Sandhya Jayasekara led the effort, programming several yeasts (including baker’s yeast) to convert plastic- and biomass-derived molecules into proteins, vitamins and flavourings.

Why It Matters

Facing a projected rise in global food demand and escalating plastic pollution, the SIU approach seeks to address both issues by turning waste streams into food ingredients. The researchers describe plastics as carbon-rich substrates that can potentially be rebuilt into macronutrients like protein, offering a route to produce sustenance in resource-constrained environments such as disaster zones or deep-space missions. The work aligns with NASA’s exploration goals and broader efforts to upcycle waste streams into edible products using biotechnological methods rather than traditional chemical processing.

Background

The project is connected to NASA’s Deep Space Food Challenge, which seeks new food technologies for long-duration spaceflight. The team uses a process they term oxidative hydrothermal dissolution to break down PET plastic and other biomass into smaller, microbe-accessible fragments. Yeasts are then employed as production systems to convert these fragments into proteins, vitamins and flavorings, moving away from conventional extraction routes and toward in situ biomanufacturing of food components. The research underscores a shift toward carbon reuse, leveraging plastics as a carbon source alongside agricultural waste.

Key Facts

• SIU Carbondale researchers programmed several yeasts, including baker’s yeast, to transform plastic- and biomass-derived molecules into proteins, vitamins and flavourings.
• Materials processed included PET plastic and discarded corn stalks/leaves, using oxidative hydrothermal dissolution.
• The end product is a protein-rich cookie concept named µBites, prepared by combining microbial ingredients with fibre, starch and sweetener and extruded via a 3D printer.
• The work is linked to NASA’s Deep Space Food Challenge and was presented in the context of an ACS meeting in Chicago in 2026.
• The team is led by Associate Professor Lahiru Jayakody; graduate student Sandhya Jayasekara contributed to the work.
• Initial data suggest the cookies are safe to eat, but taste testing awaits institutional approval.

What Happens Next

The SIU team intends to continue validation and safety assessment for the edible product and to advance the process toward potential field or space-environment testing under NASA’s program. A formal presentation of the findings is planned for the ACS Fall 2026 meeting, with ongoing work focused on optimizing yield, flavor, and nutritional content of the µBites cookies.