Two new enzymes can break down one of the numerous common single-use plastics, reveals a study by Brunel University London in the journal Biofilms and Microbiomes.
Faster Process – Plastic-eating enzymes
They could be developed to dissolve plastic bottles faster than current recycling methods and create the raw material to make new ones.
Water-polluting plastic waste is a huge problem, with most everyday single-use plastics destined for landfills, which take hundreds of years to decompose.
Tackle the waste crisis
Bacteria show potential to help tackle the waste crisis, with scientists pinpointing several new species that encode enzymes that can degrade plastic. But these enzymes degrade plastic too slowly to be helpful.
Two new PET-degrading enzymes
“These new findings are fascinating,” said Dr Ronan McCarthy. “Not only have we identified two new PET (Polyethylene terephthalate) degrading enzymes, but we found a way to improve their degradation abilities by modifying the bacteria as a whole, rather than modifying each enzyme individually.”
Biomedical scientists at Brunel are doing extensive research in synthetic biology to find ways to make these beneficial plastic-degrading enzymes work harder.
Synthetic biology uses ideas from engineering to design new biological pathways, organisms, and devices and to modify ones found in nature. In this fresh study, they use the techniques to boost bacteria’s abilities to grow in communities called biofilms.
Like people, bacteria don’t often like living on their own.
Plastic-eating enzymes Bacteria living together in biofilm ‘communities’ can share nutrients and communication signals and withstand extreme temperatures and chemical hazards better.
The team genetically engineered plastic-degrading bacteria to attach to the waste plastic and form biofilms.
It ramped up the concentration of the enzyme around the plastic, making it much more powerful and better at breaking it down. “This suggests that modulating biofilm formation may be an effective strategy to increase the efficiency of plastic degrading bacteria,” said Dr McCarthy. “Using biofilm to enhance plastic degrading enzyme activity could potentially be applied to all plastic degrading enzymes currently in development.”
Biofilms form on many natural surfaces like soil, water, and rocks. In health settings, bacterial infections such as MRSA can 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,” added researcher Dr Sophie Howard. “We also aim to further harness synthetic biology to give even greater control over biofilm formation.”