Our land and our seas are contaminated by large amounts of
non-biodegradable plastic. To cite one example, the Mediterranean Sea alone
could contain about 250 billion plastic fragments, about 500 tons of material,
according to an estimate of Ifremer and the University of Liege, published in
December 2010.
These fragments are not without importance for the marine
environment, since they can be eaten by fish and accumulate along the food
chain. Even with all the consequences associated with ingestion of these
particles are not yet known, it is necessary to find new materials whose
resistance is similar to the plastics industry, but have the advantage of being
potentially biodegradable. The solution to this complex problem could come from
bees belonging to the family Colletidae.
These bees only live mostly in the northern hemisphere.
During playback, the females burrow before laying their eggs. To maintain eggs
protected from temperature changes and different risks (bacteria, parasites, and
fungi), "polyester bees" secrete a cellophane material. They use this
compound to surround the nest chamber with a protective layer in which the
larvae are able to grow and develop safely. It is in these layers in which a
team of researchers from the Franklin W. Olin College of Engineering (USA),
including Debbie Chachra, have pinned their hopes for the development of a new
bioplastic.
Having obtained this biomaterial samples, the researchers
were able to account for the extreme resistance of the fibers forming the
protective layer, which have not been able to break the material normally used.
This is where the plastic is different from all those that have been
synthesized by other methods. Researchers, however, noted that the material
produced is not composed exclusively of plastic. The synthesis of the
protective layer is in two stages. Initially, the nest chamber is covered with
silk fibers. Plastic molecules are added in a second stage. The result is
similar to the fiberglass material. The various substances used in the
composition of bioplastics (mainly the
18-hydroxyoctadecanoic-hydroxyéicosanoico acid and 20) are secreted by a gland
in the abdomen of bees, according to Suzanne Batra W. Introduction of
Beneficial Insect Laboratory (USA.). The bioplastic produced is hard and its
structure does not deteriorate over time. In addition, it is perfectly
waterproof.
At present, no known method allows to decompose this
bioplastic. That's why Debbie Chachra and his team have turned their gaze to
bacteriologists. His wish: to find a bacteria capable of breaking the plastic
produced by bees. Such a discovery would produce a large number of everyday items
not degradable without bacterial action. Once past life object could be
digested by bacteria and substances created can be used again. Finally, the use
of such degradable bioplastics potentially reduces the number of plastic waste
going to landfill.
The results of the research team
on the mechanical properties of plastics produced by bees have not yet been
published, but the truth is that its work should be followed with great
interest.