Employing Microbes to Convert Food and Foodware Wastes into Resources

March 28, 2022
Biology research student Belle Ehrmantraut examining a PLA-degrading bacterial culture.

Biology research student Belle Ehrmantraut examining a PLA-degrading bacterial culture.

Michael Cohen

If you’ve eaten on campus, it is likely that you’ve encountered disposable foodware labeled “Compostable.” You might expect that these should be placed in the Compost waste bins but unfortunately, they actually belong in the Landfill bins. Sonoma State Culinary Services uses containers, utensils, plates, and cups made of polylactic acid (PLA) bioplastic that technically meets the standards for classification as compostable but they cannot currently be processed by most commercial composting facilities due to the slow rate of PLA degradation. 

In my research laboratory, Biology student Belle Ehrmantraut and I have been working to develop biologically-based means to speed the degradation of PLA bioplastics that may someday allow Sonoma State to biodegrade all of its disposable foodware on campus, and maybe even generate some energy in the process! Briefly, our experimental system utilizes the degradative capacity of a PLA-adapted microbial community to break down the bioplastic into biomass and soluble molecules. Energy can then be extracted from this material by combining it with food waste within an anaerobic digester, which produces methane-rich biogas. 

Combined processing of our food and foodware wastes in this manner would contribute in many ways to improving the sustainability of our campus operations, including lowering air pollution and traffic congestion by reducing the need for trucking of waste to treatment sites, and by providing internally generated sources of renewable energy and compost for landscaping. 

We will be presenting on the promising results of our research in a poster at the SSU Science Symposium on Tuesday, April 26, 3:30 to 6:30 pm.

Funding for our research has been generously provided by the Center for Environmental Inquiry Faculty Grant for Sustainable and Environmental Inquiry and a Student Research Award from the Office of Research & Sponsored Programs. All PLA foodware used for our experiments was kindly provided by World Centric of Rohnert Park.