When plastic waste contains dirty mixed polyolefin there is no many options for circular economy processes. Lately more and more attention is focussed on bioremediation methods. Very promising one relates to implementation of various beetle larvae (including yellow mealworm beetle or zophobas atratus) to transform waste plastics into proteins, fat and chitin. The proteins and fat (with no microplastics pollution) can be used as feed. However, chitin and finally chitosan, has a number of commercial and biomedical applications e.g. as biopesticide, antibacterial agent or for self – healing polyurethane paint.

Upcycling of dirty mixed plastics

• What it is: the upcycling method
• How it works: the larvae of various beetles are fed with plastics and transfer it to high value products: proteins, fat and chitin
• Purpose: utilisation of dirty, mixed plastics

Target group for this tool:

For example Café and restaurant owners. Store managers serving to go beverages and food.

Further information:

In reality there is much more larvae of mots or beetles, which can be fed by various plastics. Larvae are fed with plastics and/or paper and produce proteins, fat and chitin.

The economy issues are investigated.

Results:

In laboratory scale, it was confirmed that

• some larvae consume the plastics and paper (e.g. paper cups), their weight grows and mass of plastics (or paper) declines. To digest the plastic they use enzymes produced by bacteria from their digestion system;
• there is no microplastics in their proteins and fat;

Links:

1. Boschi, A., Scieuzo, C., Salvia, R., Arias, C. F., Peces Perez, R., Bertocchini, F., & Falabella, P. (2024). Beyond microbial biodegradation: Plastic degradation by Galleria mellonella. Journal of Polymers and the Environment, 32, 2158–2177. https://doi.org/10.1007/s10924-023-03084-6
2. Lou, Y., Ekaterina, P., Yang, S.-S., Lu, B., Liu, B., Ren, N., Corvini, P. F.-X., & Xing, D. (2020). Biodegradation of polyethylene and polystyrene by greater wax moth larvae (Galleria mellonella) and the effect of co-diet supplementation on the core gut microbiome. Environmental Science & Technology, 54(5), 2821–2831. https://doi.org/10.1021/acs.est.9b07044
3. Venegas, S., Alarcón, C., Araya, J., Gatica, M., Morin, V., Tarifeño-Saldivia, E., & Uribe, E. (2024). Biodegradation of polystyrene by Galleria mellonella: Identification of potential enzymes involved in the degradative pathway. International Journal of Molecular Sciences, 25(3), 1576. https://doi.org/10.3390/ijms25031576