Enzyme breakthrough could revolutionise plastic recycling
17 Apr 2018
Scientists experimenting with an enzyme that helps bacteria digest plastic have engineered a faster, mutant strain that could provide a breakthrough in recycling.
The University of Portsmouth and America’s Department of Energy’s National Renewable Energy Laboratory were studying a natural enzyme first identified in Japan two years ago.
It appeared to be able to break down PET (polyethylene terephthalate) plastic used for making disposable bottles.
Portsmouth professor John McGeehan, who jointly headed the research, said his team ‘tweaked’ the enzyme with the addition of amino acids and discovered the mutated version consumed plastic faster.
McGeehan described the 20% improvement in speed as “modest”. However, he said it indicated that it would be possible to optimise the enzyme further and make it still more efficient.
The enzyme structure is said to be similar to that employed to break down cutin, the naturally-occurring polymer which coats plants.
Scientists hope the process can then be scaled up to deal with the issue of plastic disposal and recycling on an industrial scale.
The intention would be to break the PET down into its component parts and recycle it back into plastic. At present plastic bottles are recycled for materials rather than used to produce new bottles.
Direct recycling would have the net effect of reducing the number of bottles created and help limit the pollution caused. Worldwide it is estimated by the journal Science that only one bottle in seven is recycled for other uses.
