Cheaper green plastics from cooking oil
Waste oil from cooking fish and chips and other fried
food could be used to create environmentally friendly plastic more
cheaply, according to researchers at the University of
The new research suggests using waste cooking oil as a starting
material in the creation of environmentally friendly plastics, or
bioplastics, could reduce the cost of production.
It has a double benefit for the environment as it also reduces
environmental contamination caused by the disposal of waste
The resulting high quality plastic is suitable for use in
medical implants and cancer therapy treatments, according to the
Wolverhampton scientists who presented their work at the Society
for General Microbiology’s Autumn Conference at the University of
A major problem of environmental pollution is that plastics
produced by the petrochemical industry are not biodegradable and
therefore accumulate in the environment at a rate of more than 25
million tonnes per year.
Bioplastics are more sustainable because they can break down in
the environment faster than fossil-fuel plastics, which can take
more than 100 years.
The Poly(hydroxyalkanoate) (PHA) family of polyesters is
synthesised by a wide variety of bacteria. The resulting biopolymer
is biodegradable and non-toxic. These bacterial PHA biopolymers
have attracted much attention as environmentally friendly
bioplastics for a wide range of agricultural, marine, and medical
applications. Poly 3-hydroxybutyrate (PHB) is the most commonly
produced polymer in the PHA family.
Currently, growing bacteria in large fermenters to produce high
quantities of this bioplastic is expensive because glucose is used
as a starting material.
Work by a research team from the School of Applied Sciences at
the University of Wolverhampton suggests that using waste cooking
oil as a starting material reduces production costs of the
Victor Irorere, who carried out the research, said: “Our
bioplastic-producing bacterium, Ralstonia eutropha H16, grew much
better in oil over 48 hours and consequently produced three times
more PHB than when it was grown in glucose.
“Electrospinning experiments, performed in collaboration with
researchers from the University of Birmingham, showed that
nanofibres of the plastic produced from oils were also less
crystalline, which means the plastic is more suited to medical
Previous research has shown that PHB is an attractive polymer
for use as a microcapsule for effective drug delivery in cancer
therapy and also as medical implants, due to its biodegradability
and non-toxic properties. Improved quality of PHB combined with low
production costs would enable it to be used more widely.
The disposal of used plastics - which are largely
non-biodegradable - is a major environmental issue.
Plastic waste on UK beaches has been steadily increasing over
the past two decades and now accounts for about 60% of marine
Dr Iza Radecka from the University of Wolverhampton is leading
the research. She said: “The use of biodegradable plastics such as
PHB is encouraged to help reduce environmental contamination.
Unfortunately the cost of glucose as a starting material has
seriously hampered the commercialisation of bioplastics.
“Using waste cooking oil is a double benefit for the environment
as it enables the production of bioplastics but also reduces
environmental contamination caused by disposal of waste oil.”
The next challenge for the group is to do appropriate scale-up
experiments, to enable the manufacture of bioplastics on an
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Date Issued: Friday, 07 September 2012