Scientists find bacteria and fungi capable of breaking down plastics

What is the plastisphere?

The team started sampling plastic wastes at Dafeng, a UNESCO-protected site near the Yellow Sea Coast, in May 2021. The team then went on to use metabarcoding analysis to identify the different strains of bacteria and fungi in the samples. 

They found the existence of a distinct, man-made ecological niche called the terrestrial plastisphere, made of plastic debris from the coast. The microbiome in the terrestrial plastisphere differed from the one found in the surrounding soil.

The team also conducted assembly analyses which revealed the influence of deterministic processes, like environmental filtering based on pH and carbon content for bacteria and carbon and cation content for fungi, in shaping the plastisphere communities.

The findings led them to conclude that unique microbiomes, such as this one, could hold the key to identifying and evaluating microorganisms that can degrade plastic, making them an extremely valuable resource.

What does this mean for plastic waste management?

Plastic degrading microbiomes could hold the key to dealing with the large amounts of plastic waste being produced and help us to tackle a global issue.

The findings of this study contribute to the growing body of research on plastic-degrading microorganisms. There have been many previous studies that have identified fungi and bacteria species capable of breaking down plastic.

The science behind plastic-degrading microorganisms is still in the early stages, and it might be quite a while before they can be used efficiently to deal with the global plastic crisis. However, the research is encouraging as it shows a potential solution.

The study was published in the Journal of Hazardous Materials.

Study abstract:

Research into plastic-degrading bacteria and fungi is important for understanding how microorganisms can be used to address the problem of plastic pollution and for developing new approaches to sustainable waste management and bioplastic production. In the present study, we isolated 55 bacterial and 184 fungal strains degrading polycaprolactone (PCL) in plastic waste samples from Dafeng coastal salt marshes, Jiangsu, China. Of these, Jonesia and Streptomyces bacteria also showed potential to degrade other types of petroleum-based polymers. The metabarcoding results proved the existence of plastisphere as a distinct ecological niche regardless of the plastic types where 27 bacterial and 29 fungal amplicon sequence variants (ASVs) were found to be significantly (p < 0.05) enriched, including some belonging to Alternaria (Ascomycota, Fungi) and Pseudomonas (Gammaproteobacteria, Bacteria) that were also mined out by the method of cultivation. Further assembly analyses demonstrated the importance of deterministic processes especially the environmental filtering effect of carbon content and pH on bacteria as well as the carbon and cation content on fungi in shaping the plastisphere communities in this ecosystem. Thus, the unique microbiome of the plastisphere in the terrestrial-marine ecotone is enriched with microorganisms that are potentially capable of utilizing petroleum-based polymers, making it a valuable resource for screening plastic biodegraders.