UK researchers discover novel PET degrading enzymes and plan industrial bioreactor testing

17 Oct 2023 --- Researchers at Brunel University, UK, have developed two novel enzymes that they say can degrade PET “faster than current recycling methods.” The team claims to have broken through previous attempts at using bacteria to reduce plastic waste, which has been too slow to be viable at an industrial scale.

According to the study authors, the findings could fast-track the development of bacterial plastic bioremediation solutions. 

“These new findings are really exciting,” says Dr. Ronan McCarthy, who co-led the research. Not only have we identified two new PET degrading enzymes, but we found a way to improve their degradation abilities by modifying the bacteria as whole rather than modifying each enzyme individually.”

The team genetically synthesized eight forms of plastic-degrading bacteria and attached them to plastic waste. They found that two of these bacteria were able to degrade PET effectively. 

The findings are published in Biofilms and Microbiomes. 

Biofilm formulation 
The researchers hypothesized that enhancing a bacteria’s ability to attach to and form a biofilm on plastic would maximize concentrations of enzymes around a target substrate and increase the rate of degradation. 

The findings show that increased polyester degradation resulted in increased biofilm levels.

“This [research] suggests that modulating biofilm formation may be an effective strategy to increase the efficiency of plastic degrading bacteria,” says Dr McCarthy. 

“Using biofilm to enhance plastic degrading enzyme activity could potentially be applied to all plastic degrading enzymes currently in development.”

The research team explains that biofilms form on many natural surfaces like soil, water, and rocks. Common bacterial infections such as Methicillin-resistant Staphylococcus aureus (MRSA) can also form biofilms that create a barrier to antibiotics and the immune system.

The team now plans to test the two new enzymes in a bioreactor. 

“We want to see if increasing biofilm formation improves plastic degradation in a more industrial-like setting,” adds co-researcher Dr. Sophie Howard. 

“We also aim to further harness synthetic biology to give even greater control over biofilm formation.”

Edited by Louis Gore-Langton