Waste colonies yield bacterium with 3 enzymes that may break down polyester

Scientists have enriched expanded polystyrene waste from a beach in Ireland to isolate a bacterium shown to contain three enzymes that could break down polyester.

The team, from Brunel University London, is studying microorganisms that can degrade plastic, in the hope the microorganisms or their plastic-degrading enzymes can be used to manage the growing plastic waste problem.

"If microorganisms can degrade plastic that cannot be recycled, this will reduce the amount of plastic that is incinerated and landfilled," said corresponding author Dr. Ronan McCarthy.

"Many of the known plastic-degrading microorganisms and enzymes have naturally low efficiency, so we need to select for organisms that have higher efficiency or engineer the enzymes to work better. We found that native plastic waste communities can be enriched for communities that have better degradation activity through our enrichment experiment.

The team collected native bacterial communities from environmental waste plastic and then conducted an enrichment experiment to find communities that had improved plastic degrading abilities after only having the plastic waste as a carbon source. They observed a change in community composition, and identified a strain of Pseudomonas stutzeri that had three putative enzymes that could have a role in polyester degradation.

Image source: Howard et al. (2023), Environmental Microbiology.