Scientists are turning yogurt waste into biodegradable plastic for food packaging.

The production of Greek yogurt is particularly resource-intensive, as it creates approximately three liters of toxic acid whey for every liter of yogurt produced. In 2017, researchers at Cornell University and the University of Tübingen published a study in the journal Joule detailing a method to convert this waste into useful chemicals. They utilized a 'reactor microbiome' consisting of diverse bacteria to transform the sugars and acids in the whey into more complex molecules.The process specifically targets lactic acid and lactose, converting them into caproic acid and caprylic acid. These compounds can be further processed into polylactic acid (PLA), a versatile biopolymer used extensively in the 3D printing and packaging industries. PLA is a biodegradable thermoplastic derived from renewable resources, offering a significant carbon footprint reduction compared to petroleum-based plastics like polyethylene.Globally, the dairy industry generates over 160 million tons of whey each year, much of which is difficult to dispose of because its high acidity can disrupt aquatic ecosystems if dumped. By utilizing the 2.5 million tons of acid whey produced annually in the United States alone, scientists hope to create a circular economy. This innovation not only prevents environmental contamination but also provides a sustainable alternative to traditional plastics that can take up to 450 years to decompose in landfills.