Turning food waste into eco-friendly plastics with the power of bacteria
Researchers at the University of Waterloo can now make eco-friendly plastics using bacteria that feed on food scraps from your table. Unlike animals that store fat when they consume excess food, these bacteria store a biopolymer. Biopolymers are natural polymers produced by the cells of living organisms that are fully biodegradable. The biopolymer can be used in multiple applications including single-use plastics.
Utilizing food waste is beneficial to the environment as it typically generates methane and carbon dioxide when decomposing in landfills contributing to greenhouse gases.
Plastics produced using this new method have many potential applications. For example, in food packaging as a plastic film to cover meat. In the biomedical field, it would be ideal for drug delivery as encapsulation materials for controlled drug release systems in antibiotic capsules. Biopolymers are also effective in tissue engineering to restore, maintain, or improve damaged tissues or potentially whole organs. In the agricultural industry, biopolymer-based mulch film can be left in the soil, and it will degrade naturally becoming fertilizer.
“Using food waste as food for bacteria which can produce bioplastics is a very exciting development,” said Dr. Trevor Charles, a professor in the Department of Biology at the University of Waterloo, and one of the authors of the study. “This approach is significant because it has the possibility to reduce the cost of creating biopolymers.”
The primary focus of this research is on a bioplastic called polyhydroxyalkanoates (PHAs), which is ecofriendly because it degrades naturally into benign byproducts in garden composts, agricultural fields, fresh water, or even seawater, without leaving harmful plastic pollution or toxic chemical residues.
Despite PHAs being more environmentally friendly, they are expensive to produce. Two main factors contribute to the high cost: the production process itself and the use of expensive raw materials, such as food resources like starch from corn or other crops that compete with food and animal feed production. This competition for resources also raises concerns about sustainability and the ethical implications of diverting food for industrial use.
“Currently, the process of breaking open the bacterial cells and recovering the polymer is costly. The team is working to develop an efficient and cost-effective extraction method that would make the overall production process more viable for large-scale commercialization,” said Tizazu Mekonnen, a professor in the Department of Chemical Engineering. “This research not only offers a pathway to reducing the environmental impact of plastic waste, it also supports a circular economy by turning food waste into a valuable resource.”
The next steps in this research involve optimizing and scaling up the extraction process for the biopolymer. The team is actively working on scaling up the production process and commercialization.
This study was recently published in ACS ES&T Engineering journal.