Discarded plastic bottles for dinner: Waste turns into edible protein snacks

Researchers from Southern Illinois University Carbondale, led by Lahiru Jayakody, have developed a method to produce edible protein cookies using polyethylene terephthalate (PET) from plastic bottles and agricultural waste. The process combines chemical polymer degradation with a consortium of genetically modified yeasts to transform waste into food ingredients. The results were presented at the American Chemical Society meeting in Chicago. The Two-Stage Transformation Process The production method consists of a chemical decomposition stage followed by a biological synthesis stage. First, a mixture of PET plastic and corn stover—the stems and leaves remaining after harvest—undergoes oxidative hydrothermal liquefaction. This involves treating the material with water and oxygen under high temperature and pressure to break polymers down into low-molecular-weight compounds accessible to microorganisms. The resulting hydrolysate serves as a substrate for three specific types of yeast, each fulfilling a distinct biological function: