SUSTAINABILITY AND THE ENVIRONMENT: BIOTECHNOLOGY
PHOTO: UPIX
PHOTOGRAPHY
Professor
John McGeehan
Not surprisingly
the University’s
enzyme research
– now housed
within the newly
established
Centre for
Enzyme
Innovation (CEI)
– has attracted
worldwide
attention and
acclaim among
scientists,
governments and
also the plastics
industry itself.
The team was
recently awarded
the Times Higher
Education STEM
Research Project
of the Year.
Our new ‘biotech’ ally
Another family of enzymes has been found that can be
engineered to break down plant waste and help convert
it into high-value materials such as nylon, plastics and
other polymers.
This has the potential, if scaled up, to achieve two
sustainability goals: to give waste, particularly crop waste, a
commercial value while also replacing petroleum-based feed
stocks for such products with low-carbon renewables.
The latest development was announced in mid-2019
by a UK–US enzyme engineering team at the University
of Portsmouth and the US Department of Energy's National
Renewable Energy Laboratory (NREL).
The team’s newly engineered enzyme is active on a key
component of lignin. Currently, this valuable material is
primarily burned, and scientists have been trying for decades
to find a way to break it down efficiently.
Professor John McGeehan, Director of the Centre for
Enzyme Innovation at the University, says the finding arises
from the researchers’ pursuit of enzymes in nature that
can be brought into the laboratory, studied to see how
they work, then engineered to produce new tools for the
biotechnology industry.
“In this case, we have taken a naturally occurring enzyme
and engineered it to perform a key reaction in the breakdown
“It allows us to see the 3D atomic structure of
PETase in incredible detail,” says Professor McGeehan.
“Being able to see the inner workings of this
biological catalyst provided us with the blueprints to
engineer a faster and more efficient enzyme.”
Chief Executive of the Diamond Light Source,
Professor Andrew Harrison, says the beamline is proving
invaluable for tailoring the enzyme for large-scale
industrial recycling processes: “The impact of such an
innovative solution on plastic waste will be global. It is
fantastic that UK scientists and facilities are helping to
lead the way.”
In recognition of the achievement to date, and to
help drive the researcher further, the UK Government
has recently allocated £5.8 million from the Research
England Expanding Excellence Fund.
This will further extend the capabilities of the CEI.
The government support, coupled with significant
investment by the University of Portsmouth, will speed
up progress towards finding biological solutions to one
of the world’s greatest environmental challenges –
plastic waste.
Universities and Science Minister Chris Skidmore said:
“Pushing the boundaries of knowledge and conquering
new innovations are what our universities are known for
the world over. This programme led by the University of
Portsmouth will look at how enzymes can break down
single-use plastics and help cut plastics pollution.”
of one of the toughest natural plant polymers – lignin.
“To protect their sugar-containing cellulose, plants have
evolved this fascinatingly complicated material that only a
small selection of fungi and bacteria can tackle. However,
lignin represents a vast potential source of sustainable
chemicals, so if we can find a way to extract and use those
building blocks, we can create great things.”
Lignin acts as scaffolding in plants and is central to water
delivery from roots. It provides strength and also a defence
against pathogens.
“It’s an amazing material,” says Professor McGeehan.
“Cellulose and lignin are among the most abundant
biopolymers on earth. The success of plants is largely due to
the clever mixture of these polymers to create lignocellulose,
a material that is challenging to digest.”
Current enzymes tend to work on only one of the building
blocks of lignin, making the breakdown process inefficient. Using
advanced 3D structural and biochemical techniques, the team
has been able to alter the shape of the enzyme to accommodate
multiple building blocks. The results provide a route to making
new materials and chemicals such as nylon, bioplastics and even
carbon fibre from what has previously been a waste product.
The discovery also offers additional environmental benefits
– creating products from lignin reduces the world’s reliance on
Professor McGeehan, who is also the Centre’s Director,
says the facility and its researchers are now focusing on
finding enzymes capable of breaking down different types
of plastic and then engineering these to be fast enough
to be deployed at industrial recycling facilities.
The Centre has three teams: one focused on finding
new enzymes in the environment that can break down
different types of plastics; another to engineer these
enzymes and systems to make them more efficient
and robust; and a third to work with industry partners
to make these engineered enzymes suitable for
large-scale production.
“From David Attenborough’s Blue Planet II through
to his latest programme, Climate Change – The Facts,
we are all now increasingly aware of the urgency of
tackling plastic pollution and climate change,” he says.
“It is of the utmost importance that the UK
Government has recognised the need to fund research
and innovation to take our fundamental science through
to real-world industrial and environmental applications.”
The University of Portsmouth’s Vice-Chancellor,
Professor Graham Galbraith, says the importance of the
science that will help the world address “one of the most
pernicious pollutants of our age” can’t be understated.
“One of the overarching goals of our research
strategy at the Centre is to focus researchers’ minds,
time and effort in addressing the most pressing
problems facing the world.”
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ISSUE 1 / 2020