As a further chapter in my occasional
highlight of serendipitous
discoveries, teams of scientists from the UK and the U.S.
discovered and evolved in Japan an enzyme that can degrade plastic by assisting
a bacterium with digesting PET plastics.
Ongoing further research promises to put a relatively cheap end to worldwide
plastic pollution by recycling it sustainably. As it stands today, PET plastics can survive hundreds of years
in the environment and have turned into an increasingly serious and mushrooming
burden to major countries and large oceanic regions. Researchers from the University of Portsmouth, UK and the Renewable Energy Laboratory at
the U.S. Department of Energy have now discovered, and published
in PNAS, a potential solution to this blight by
studying and tuning the structure of a natural enzyme that developed on its own
in a Japanese waste recycling center. Initial research found that the PETase enzyme assists a
bacterium, Ideonella
sakaiensis 201-F6, with breaking down or digesting PET
plastics. The enzyme structure was then optimized by bioengineering by adding
some amino acids. This optimization process resulted in random changes to PETase’s
activities and ultimately indeed an altered enzyme that turned out to be significantly
more effective than its natural form. The same team now continues to explore
the enzyme further to see if PET plastics can be degraded on an industrial scale, and if so, with what side effects. It
is entirely possible, indeed likely, that the next few years will yield industrially
viable processes to disassemble PET and possibly other plastics back into their
original organic building blocks to set in motion a sustainable chain of
recycling. Independent scientists not directly involved in this research consider
this biodegradability approach clearly promising despite the obvious concerns
that the development of the enzyme as possible solution against pollution is
still at too early a stage to render a meaningful assessment possible. And that may
well be true, but it is also secondary: enzymes are non-toxic, biodegradable
and capable of being produced in large quantities by microorganisms, and there is
great potential for using enzyme technology to solve society's growing waste and
landfill problem by degrading at least some of today’s most commonly used plastics. Even as it may still be necessary to
await further developments intended to improve the enzyme, this discovery
brings sustainable recycling of plastics within striking distance.
