SCIENTISTS at the city’s university have inadvertently engineered an enzyme which can digest some of our most commonly polluting plastics, providing a potential solution to one of the world’s biggest environmental problems.
The research was led by teams at the University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory (NREL) and the discovery could result in a recycling solution for millions of tonnes of plastic bottles, made of polyethylene terephthalate, or PET, which currently persists for hundreds of years in the environment.
Professor McGeehan, Director of the Institute of Biological and Biomedical Sciences in the School of Biological Sciences said: ‘Few could have predicted that since plastics became popular in the 1960s huge plastic waste patches would be found floating in oceans, or washed up on once pristine beaches all over the world.
‘We can all play a significant part in dealing with the plastic problem, but the scientific community who ultimately created these ‘wonder-materials’, must now use all the technology at their disposal to develop real solutions.’
The researchers made the breakthrough when they were examining the structure of a natural enzyme which is thought to have evolved in a waste recycling centre in Japan, allowing a bacterium to degrade plastic as a food source.
The goal was to determine its structure, but they ended up going a step further and accidentally engineered an enzyme which was even better at breaking down PET plastics.
‘Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception,’ Professor McGeehan said.
‘Although the improvement is modest, this unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics.’
The researchers are now working on improving the enzyme further with the tools of protein engineering and evolution to allow it to be used industrially to break down plastics in a fraction of the time.
The research was funded by the University of Portsmouth, NREL and the Biotechnology and Biological Sciences Research Council (BBSRC).
The paper’s lead author is postgraduate student, jointly funded by the University of Portsmouth and NREL, Harry Austin.
He said: ‘This research is just the beginning and there is much more to be done in this area.
‘I am delighted to be part of an international team that is tackling one of the biggest problems facing our planet.’
Dr Colin Miles, Head of Strategy for Industrial Biotechnology at BBSRC, added: ‘This is a highly novel piece of science based on a detailed molecular-level understanding of an enzyme able to depolymerise a common type of plastic, whose persistence in the environment has become a global issue.
‘It will be interesting to see whether, based on this study, the performance of the enzyme can be improved and made suitable for industrial-scale application in the recycling and the future circular economy of plastic.’
It comes after a national push against single use plastics.