Monash University researchers have developed natural plastic films made from food waste sugars that could offer compostable alternatives to petroleum-based packaging.
The study, led by Edward Attenborough and Dr Leonie van ’t Hag from the Department of Chemical and Biological Engineering, details how the team converted food waste sugars into polyhydroxyalkanoates (PHA) biopolymers, biodegradable plastics produced by bacteria. The films could be used in packaging applications such as food wrap and agricultural films, including silage wrap.
By feeding two soil-dwelling bacteria, Cupriavidus necator and Pseudomonas putida, a controlled mix of sugars, salts and nutrients, the researchers were able to trigger the bacteria to produce natural plastic inside their cells. These were then extracted, cast into ultrathin films around 20 microns thick, and tested for strength, stretch and melting behaviour.
Attenborough said the study shows how food waste can be transformed into “sustainable, compostable ultrathin films with tunable properties”.
“The versatility of PHAs means we can reimagine materials we rely on every day without the environmental cost of conventional plastics,” he said. “By tailoring these natural plastics for different uses, we’re opening the door to sustainable alternatives in packaging, especially where they can be composted along with food or agricultural waste.”
The researchers found that combining the stiffer plastic produced by C. necator with the softer version made by P. putida allowed them to fine-tune the films’ flexibility, strength and melting point.
The Monash team is working with Enzide and Great Wrap through the ARC RECARB and VAP hubs to explore potential commercial uses for the biodegradable materials in packaging and medical products.
The research builds on earlier Monash work that examined the potential of PHAs for use in drug delivery systems.
