Polyurethane is used
in many products:
Construction materials,
footwear, refrigerator
components and
skateboard wheels,
for several examples.
The polymer is lightweight,
an insulator, and flexible.
But recycling it is
energy-intensive,
so most polyurethane
(PU) ends up in landfills.
In the landfill,
PU can release
a variety of toxins,
some of them
believed to be
carcinogenic.
Most prior studies
investigated the ability
of bacteria and fungi
strains to break down
oil-based plastics.
Few studies
ever looked at
polyurethane.
Scientists surveyed
bacteria communities
living among plastic waste.
They identified
Pseudomonas sp. TDA1.
The bacteria targeted
the chemical bonds
that form polyurethane
plastics -- they "ate"
polyurethane.
Those bacteria were
also part of a family
of bacteria known for
their ability to withstand
toxins.
"That trait is also named
solvent-tolerance
and is one form of
extremophilic
microorganisms,"
said co-author
Christian Eberlein,
scientist at the
Helmholtz Center
for Environmental
Research-UFZ.
Scientists hope further
genomic investigations
will reveal the extracellular
enzymes, or exoenzymes.
Exoenzymes are what
the bacteria use to trigger
a compound-degrading
biochemical reaction.
Scientists
hope to engineer
similar bacteria that
more efficiently degrade
polyurethane compounds.
Researchers detailed their
discovery recently
in the journal Frontiers
in Microbiology.
"The bacteria can use
these (PU) compounds
as a sole source of carbon,
nitrogen and energy,"
said study co-author
Hermann J. Heipieper,
senior scientist at the
Helmholtz Center
for Environmental
Research-UFZ
in Leipzig, Germany
and co-author
of the new paper,
said in a press release.
"This finding represents
an important step
in being able to reuse
hard-to-recycle
PU products."